Small Engines (Lawn Mowers, etc.): chraftsman chipper shredder model 247-776350, chipper shredder, engine shaft

Question
I've had this 7.5 hp unit for about a year (second hand from a person who only used it once so it was like new). I have worked it pretty hard around the property and had a couple of flail failures which I have replaced. Due to these failures and the type of stuff I put thru I remove the main chute and half of the chamber so that I can inspect the flails and insure the pins are in place.
Today I noticed that the chute assembly seemed loose and so I took off the part I normally remove so I could inspect the mounting bolts but they are behind the impeller/flail assembly. I did not get a manual with this unit so I don't have any good documentation on the assembly. The bottom line is "how do I remove the impeller / flail / flywheel assembly?".
I removed the bolt which seems to hold it and the blade in place but the fly wheel / impeller is not budging. MY options seem to be it's threaded onto the engine shaft and if so left or right handed threads or it's a press fit and I just slam it with a slide hammer? I'm a little reluctant to slam it with the slide hammer.
Any assistance would be appreciated.

Answer
 Hello Wes:

 Go to this Addy http://www3.sears.com/ and Click on the Lawn Equipment Block. Follow the Directions to the View Parts Diagram Page. Here you can See the Breakdown of the Chipper/Shredder. The Impeller is Keyed to the Shaft and you will Require a Puller to Remove it. I have had some Impellers so Frozen to the Crankshaft that I have had to use Heat to Finally Remove them from the Engine. Hope this Helps. Let me know what Happens, Please.

 Good Luck

 Respectfully

 John