Leaving aside the question of if thawing a giant Yeti is a good idea (it's probably not), the Yeti thawing plan appears to be
1) reduce the size of the ice block with flamethrowers
2) put the Yeti in a giant open box
3) lift the box with the helicopter to the altitude of the Himalayas
4) spray the Yeti with hot water until the Iced Yeti is a Normal Yeti.