Step 1: Turn on power
Handle: in spawn on a bench
Fuse: in spawn on a barrel or the counter thing across from quick revive
Box: in second area near left side soul chest
You can build it at the beach on the side of one of the little bungalo things lol.

Step 2: PAP
Turn 4 red valves around the map
1st valve- in water near pirate ship by the net
2nd valve- far left of the wooden door in the ice cream area
3rd valve- near the "skull bay" sign
4th valve- to the left of change chews perk machine in the space area
Link the teleporter, button is on a wall, if you go through the building that looks like an antique shop, take a right and go through the little cave-looking tunnel, it'll be right there

Clipboards/panels:
You must punch the number from the clipboard into the nearest panel.
1st clipboard is in the ice cream area leaning against an ice cream stand,
The panel is on the bridge to the ice cream area

2nd clipboard is leaning against a yellow floaty on the water slides,
The panel is on the beach near the "bar"

3rd clipboard is leaning against the cosmic tunes store in the area next to the pap teleporter,
The panel is in spawn to the far right of quick revive
Link PAP teleporter with red button on the wall near...I don't remember...you'll know it when you see it.

Step 3: Neil
Teleport to PAP and grab neil's head off of the barrel.
Put Neil's head on him and talk to him. He'll ask for a red battery.

Step 4: Red battery
You'll need to go back into the PAP area once you've talked to Neil and grab the dynamite in front of the ghost.
Take it to the wooden door in the ice cream area and explode the door.
You'll need to escort David Hasselhoff to the beach, he'll then go out into the water and retrieve the red battery for you.
Take it to the boss teleporter (the one near pap teleporter pad) and put it in.
Speak to Neil again and do his challenge.
After, he should give you a coin and a pair of glasses. Put the coin into one of the souvenir machines.
Speak to Neil again.

Step 5: Green battery
You'll need to put the sunglasses on and go to the area just outside spawn (where the octopus tentacles are lol) and look on the metal wall to the right. There should be some arrows. They will correspond to the arcade machines in the space area. Input the code into the machines and the box directly across from the arcade machines will blow up revealing the green battery, which you can now pick up and take back to the boss portal again.
Speak to Neil again, he'll give you another coin to place in the souvenir machine. Speak to Neil again and do another challenge.

Step 6: Blue battery
Find the red X located on the lighthouse and shoot it. It will shine on the location of a box. If you're standing on the beach facing the teleporter, take a left and go all the way through the cave, once you're out take an immediate right and go up the hill until you can take another right, the box will be right in front of a souvenir machine. Knife the box and grab the key. Take the key back into the cave area you just came out of and unlock the cage with the skeleton in it. Finish the lockdown and grab the blue battery from the cage. Take it back to the boss portal and speak to Neil again and do the final challenge you'll need to do. He will give you a bucket and your final coin to put into the souvenir machine.

Step 7: Yellow battery
Take the bucket that Neil has just given you to the beach where David went into the water, fill the bucket with the neon blue water and RUSH to the souvenir machine that you've put your coins into. This will give you a Water Gun wonder weapon (there are different variants depending on which souvenir machine you use). Take the Water Gun to the space area near the blue waterslide and shoot the battery sticking out of the ice arch above the bottom of the slide. Ride the slide to pick it up. Take it back to the boss portal and fill the boss portal with souls.

Boss fight:
There are 3 phases, you'll need to put on the sunglasses to see his weak points in between his attack phases. You'll be locked in on the beach and zombies will constantly spawn.
Buyable ending is at boss portal.

Good luck!

ps. there are also some side EE's on here, let me know in the comments if you'd like me to make another text guide on all of those. Thanks!