Chainsaw Repair

I use the special clutch removal tools.  This video shows 'an alternative' method with a screwdriver, if you are willing to take a chance - of course, he is doing this on a brand new saw, so things always go better (occurs around 3:17):   
 

Note that if you are changing from a spur to a rim sprocket, you may also need to change your oil pump gear, as the end of the spur or splines drives this gear.  This was an unexpected surprise on my Husqvarna 353.

Philbert