I believe the OP has a neo-angle corner shower. If that's correct, then the 3 panel shower wall/door that he's asking about is an aluminum frame with an outswinging door as the center panel and two stationary smaller glass panels, one on each side.
Typically, this style door is assembled with silicone to prevent leaks and is not easily disassembled. I'd suggest jockeying it into the bathroom, fitting it to the shower pan, if it fits properly, then devise some way to secure the ends to the trailer walls/shower surround. I wouldn't attempt to take it apart, if you bend the aluminum it will never fit properly and while trying to separate the parts, you'll probably twist, bend or torque the aluminum channels.
As a consideration, the glass shower panels are available at Trekwood. If what I read is accurate, that assembly costs about $326.80 plus shipping which I'd guess would be around $150.
http://www.trekwood.com/products/294...Glass-Platinum
ADDED: The shower door/wall assembly sits in two vertical aluminum channels, one on each trailer wall. The entire assembly is only attached/screwed to the trailer at those vertical channels. The bottom of the glass/aluminum wall sections rides on the shower base and is sealed with silicone. If you attempt to fasten that part to the trailer/shower base, you'll probably break it while towing. The movement of the trailer walls and the shower base/trailer floor will twist/torque the glass/aluminum and cause it to break.