Small Engines (Lawn Mowers, etc.): Replace Briggs & Stratton blade housing, sears craftsman, craftsman model

Question
QUESTION: Can you tell me how to replace the blade housing on my B & S engine?  It's a 7 horse Craftsman model #917378941.  I got the new housng and key.hi.pro from Sears. Can I do this from under the mower deck or do I need to pull the engine?  How do I get the old housing off the shaft and the new back on?  
Thanks.
Steve Eden
ANSWER: Send me the model number of the mower and I'll let you know. What is blade housing, are we talking about the part you actually bolt the blade to?

---------- FOLLOW-UP ----------

QUESTION: Sears Craftsman mower MODEL #917-378941.  
Serial #031204M 024126.  Yes, what I call the BLADE HOUSING is the part the blade bolts to.

Answer
You will need to get a 2 jaw puller and pull the old blade hub off.
Some times if you put the bolt almost all the way back in and tap it HARD with a big hammer while pulling out on the hub it will break free and come off.
Unfortunately there is also the possibility that the hub is seized up like Hoagies' goat and the "Hounds Of Hell" can't get it off.If this is the case you will have to cut it off however you can. Hacksaw, chisel, cutting torch,etc.
!!!!!!!!!!!Be extremely cautious, fuel vapors will be abundant, BOOM!!!!!!!!!!!!!!!!!