There are a couple different guides you can use
If you like video format, Chloe Spencer's is good: https://www.youtube.com/watch?v=T33GjK30ydI
There's also a guide to all endings (including Adam) in the Steam community: https://steamcommunity.com/sharedfiles/filedetails/?id=2570712524
Remember that you'll need to beat the game once first to unlock the difficulty settings, since both these guides rely on Easy mode for Adam