I just did this to my Vector this year. There is no need to remove the engine as some legends have suggested...
Remove rear skid
Remove chaincase & drive shaft
Remove belly pan inspection cover
Remove secondary clutch
Remove elbow fitting on chaincase side
Remove Rear Engine Bolt (Really long carriage bolt)
Drill out ~ 50 rivets
You need to greatly consider buying an air-over-hydraulic rivet gun to ensure that you properly pull the rivets. This heat-X also serves as a structural frame member, so it must be secured properly.
Also, since you have so much of the sled apart, you should consider replacing the driveshaft bearings (especially the one on the clutch side) and the chaincase seals & o-rings. You might even consider replacing your track if that is something you plan to do soon. Also, be sure to order enough rivets with some spares. I ordered 60 of them and had about 10 spares. You don't want to be cut short to complete the job because of a 47 cent rivet!
Proof it can be done without removing the engine is attached.
