Blower motor 90 olds cutlass

hello there i need help i got a 1990 olds cutlass supreme international i traded a car stereo for it in awsome shape but theres no blower motor was taken out because it was fried now i bought one from the scrap yard and cant seem to get it in because theres no room can anyone help me figure out how to get more room or how to get it in without cracking the rat cage