Revised direction
Hi Och, I trimmed the parts pretty well and then heated both parts with a hair dryer.Yes I did put the pants into the shirt If you don't it does get pretty 'tall' as the leg section is pretty long on that. I glued them with super glue and activater. OH, the torso seems to be rather 'thin' or skinny, you may want to pack it with wadded up plastic bags or something to fill & firm it. I didn't and he looks kind of undernourished from the side!!
Good luck & let us see the results !!
Dabbler