UV Mapping problem

[Gyrosphinx]

Hi, I really have a problem, I was trying to remap textures of my Goblin Medic, so that his chest was going to match the shredder instead of the marine model. I forgot to Backup the model, and I managed to screw op his entire chest. Can anyone help me remapping the model, I am afraid I'll only do it worse. (Btw: if u do, plz remap so his chest, shoulders, and lower feet match the Shredder's. Ty.)