How to find out where the screws go iPhone 4?

My iPhone 4 stopped getting service after dropping it so I removed the back and took out the screws and removed the antenna/speaker assembly but now I have 16ish screws and I have no idea where they go and what screw is which? Please help thank you in advance
P.s I would like answers that don't cost me anything

Here is a link to a complete tear down of the iPhone 4:

http://www.ifixit.com/...rdown/3130