How can I separate a working samsung s4 lcd screen from frame or body.

I just got this new galaxy s4 Lcd screen + frame for my broken phone. upon an attempted replacement . i found out that my old phone board wouldn't fit on the new frame+ screen i just got. so my question is.How can i separate the lcd screen from the bezel frame?..and what are the chances of me salvaging a working screen from the process.Mind you returning the screen isn't an option.