2005 Ski-Doo Racing Handbook, Page 363Get this manual
SECTION 082005 MX 550 AND 380 FC
NOTE: The PTO cylinder or fan housing have to be removed to give access to MAG piston pin with the pullerUse piston pin puller (PN 529 035 503) along with 20 mm sleeve kit (PN 529 035 542) and locating sleeve (PN 529 023 800)NOTE: The locating sleeve is the same that contains new cageless bearingInsert piston pin puller (PN 529 035 503) making sure it sits squarely against piston
Pull out piston pin no10 by unscrewing puller until shouldered sleeve end is flush with thrust washer of piston pin bearing