If you haven't figured it out yet, it's crazy simple.
1) get Cheat Engine
2) enter the 'make room' screen for an AI mission. select easy mode prison break escape (where you can select from 1-5 players.)
3) enter a player value (let's say 5) and alt+tab out of the game. open cheat engine, select AVA, and scan for a new 4 bit, exact value = 5, or whatever you entered.
4) get back in game, change the value to 2 or something
5) tab back out of the game, continue the scan with that value (2)
6) get back in game, change the value to 3 or something
7) tab back out of the game, continue the scan with that value (3)
8) continue doing that as necessary until you have localized the right address. add the address to your overview or whatever it's called, and change the value to whatever you want, and lock it. (spacebar)
9) tab back into the game, select death valley and go ahead and click make room. the value you locked in cheat engine should now be equal to the number of player slots in your room.
Cheat Engine is considered a 3rd Party Program, by using it while Playing A.V.A you are risking your account and might get banned.
I hope this helps you,I will post how to 8man if I found it out