Go to the Dropzone site, they have drawings that will help you out. It can't be too much, they are very simple guns. Broken seal? Piece of paintball jammed in it? Something like that. Which two pieces that you can't get apart are you talking about?
http://www.dropzonepaintball.com/dropzone/
Here is the addy for the Genisis 2a pics
http://www.dropzonepaintball.com/dro...Genesis_2a.jpg
Make sure your friend is cleaning and oiling after every use.