You need to watch disassemble videos on Youtube friend. There is NO GLUE used in reassembly of the iPhone 3 or 3S. There are pre-cut adhesive strips you can purchase to do the job correctly (and this is only for replacing the glass?). You take out 2 screws, the phone opens like a clam shell, then when closed back up you simply put the screws back in. iPhone 4 has a 3 part frame unlike the 3 or 3GS. The LCD is actually attached to the glass as well (best to replace BOTH for cracked glass). I hope you faired well friend!!!