Stealth kill with syringes 5 times: You can hide somewhere, then stealth kill people using syringe. This can be found in the “Orphanage Halls” part of "Rosewood" mission (On the table in the medical lab on the top floor and first floor) and the “R&D” part of “Death Factory” mission (On a crate in the bottom floor). I recommend play the "Rosewood" mission to get this playstyle.

Hide 5 bodies: After killed enemies, just always remember to hide them, if you don’t want to lose your point or get exposed.

Kill 5 people with the garrot (your key 2 weapon): This can come naturally when you play, unless you like to use your gun or just don’t want to kill anybody.

Use “Point Shooting” to kill 8 enemies: This may seem difficult, but it is not. Try to get shotgun form the police in “Derelict Building” part of “Hunter and Hunted” mission, keep the gun and at less half of instinct for the last past (Chinese New Year). Use “Point shooting” and arm the civilians crowd, take a few spot and shot. This makes 47 look like a terrorist, but is work.

Subdue 3 people: Get to the back of someone, remember to turn off your weapon by caps lock key, and press Q. Keep pressing that button until his (or her) pass out (do not break the neck). Do it 3 time and you get it

Get 9 kills with Katana: This weapon can be found in the last part of “Hunter and Hunted” mission (On a shop stand near the store clerk Larry Clay interrogates, take it after the shop guy go to avoid spotted) and the “Penthouse” of “Blackwater Park” mission (Numerous weapon displays). Use it on the count in “Hunter and Hunted” or use it on the guards in “Blackwater Park” (you can also get “Ronin” challenges if you “stealth” kill them in Samurai Armor disguise)

Get 5 kills with remote explosives.Extremely easy in “The King of Chinatown” mission. You come across on the second level, there are explosives in an alley on the left near a yellow car (go up the stairs). Grab the remote detonator, throw the explosives into a crowd and detonate it. Of course, this makes 47 look like a terrorist too.

Get 15 kills with revolver: Google “revolver” to know what is look like. In the “Birdie's Gift” mission, try to find the “Mustang Snub” gun. Grab it and run around trying to find ammo for it. Now kill everyone around.

Get 5 kills with bottles: In the “Welcome To Hope” mission, you start with tons of bottles aroud the bar. Grab one and kill one, that will start the bar fight and continue kill everyone by bottles.

Get 5 hand based combat kills: Just walk into the crowd in Chinatown and keep pressing the left mouse button (remember to turn off your weapon by caps lock key), killing everyone around. Funfact: you can do that at “Welcome To Hope” mission for more exciting.

Get 5 kills with fire axe: This weapon can be found in “The King of Chinatown”, “Shaving Lenny”, “Dexter Industries” and “Attack of the Saints”. My recommend is the “The King of Chinatown”. On the very right border of the map when you first enter; on a crate to the far left of the entrance to the alleyway to Snowman's apartment. Grab it and you know what to do next.

5 stealth kills with knives: You can found a knives in a lot of mission. “Filet Knife”, “Folding Knife”, “Kitchen Knife” and “Meat Cleaver” are all counted. Found one, grad it, get hide and kill someone.

Get 5 kills with blunt weapon: Blunt weapon is something like a hammer. In the “Hunter and the Hunted” mission, when you get in to Chinatown, stick to your left until you get to stairs leading down (This is the place where you can get the “Lieutenant Bad” Challenges). Near the garbage you will find a sledgehammer. Go kill people in the crowds or police with it. Remember to “face to face” when kill someone If you do it on their back, it will choking them and that not count.

Take damage 20 times: When you begin your fight with a gun, without hiding, this will come naturally.

Get 5 kill by thrown objects without spotted: Stealth kill someone by throwing sharp weapons. Someone say that you can use a knives to get this one but for some reason it don’t work for me. In my opinion, the best area is “Descent” in “Dexter Industries” mission. Try to get a “Screwdriver” at “Dead end” (it located in the room that have evidence). At “Descent”, you kill the first man by thrown him out of window. Get inside and kill the second guy with deadly thrown. Take the radio, thrown it to get the third guy go up and kill him by the same way. Take his key card (remember to bring your screwdriver). Get inside the lock room (there are three guy in this room), kill the first guy with your garrot (your key 2 weapon). The next two guys are reading the map, come down and wait until they apart, kill the right guy with deadly thrown, and kill the left guy with another screwdriver you can found on the low wall. Bring your screwdriver and go down the stairs, there are two guy here. Wait until they gone, go to the balcony and kill the last guy with deadly thrown, and you get it.

Get 3 kills with silenced gun without spotted: Stealth behind an enemy, bring your gun out and press Q (remember this may only work when you use “Silverballers”)

Get 2 kills via accidents: Many levels have "accidents” waiting for you to make it “happen”. In my opinion, the best place to get this one is “Shaving Lenny”. There are many "accidents” and “target” in this area, try to find all of them.

Get 5 sniper rifle kills via headshots in a row: The best place do this is “Factory Compound” in the “Dexter Industries” mission. After get out of the tunnel, you can found a Kazo TRG (a sniper rife with silence), go up the stairs and kill someone (there are 10 rounds per row anyway). And this may help you get the “Under the Bridge” challenges.

Get 3 shotgun kills while remaining undamaged: You may get this one same time with “Reaper Man” playstyle. If it don’t, do the same thing one more time.

Use 3 human shields without killing them: This works best on civilians in a crowded area like Chinatown. Take away your gun, grab someone using “x key” to have a human shield. Quickly press “Q key” to knock them out (so that they may not die from people shooting at you). Do so a few more times and you get this one.