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Achievment First Thing first

Steps to take:
1. Start the map in demolition mode (Go to play, then workshop, select the map then demolition)
2. Once the map has been started up, join the CT team.
3. Go to the right wall, jump on the ledge and over the wall. Now use your M4 to spray the feets of the terrorists (Or you can go for the wallbang).
4. After killing them, you should get your achievement. Have fun :)

Addons:
If there aren't any bots, do "bot_add_t" over and over until there is 5 on their team.
If you are unable to join CT, do "mp_humanteam any" in console.
BE SURE TO DO "sv_cheats 0" before opening up the map as having cheats on 1 will prevent the gaining of any achievements.