Legacy engine transplant

I want to put a 1.8 TBI (throttle body injection) engine from a '89 Subaru Legacy wagon into an '89 DL wagon that had a 1.8 SPFI (single point fuel injection) engine in it. Can you tell me what kind of changes I'll need to make to the DL Wagon to be able to put the Legacy engine in it. Also, will the air conditioning systems be compatible? I can tell you that the air conditioner lines are routed a little differently. Also, the instructions in the Chilton's manual tell you to take off a lot of the ancillary parts of the engine before you take the engine out. Is this necessary or can you just unhook the wires and hoses and pull the whole thing out like that? I've never attempted to do anything like this before, so any help you can give me will be greatly appreciated. Thank you, PW

BTW, this is different from the Legacy engine I'm asking for help with in this thread: http://www.automotiveforums.com/vbulletin/showthread.php?t=443543

Thanks again.