My friend has got this game and wanted me to try it, but I can only carry on from the point he has reached.

We couldn't find where the save data was stored so that we could reset the game so that I could play it from the begining

C:\Users\YOURUSERNAME\AppData\LocalLow\Gabe Cuzzillo\ApeOut

Delete all the save files and backups. Move them to another folder if you're worried.