Tools to get you going:
1/2 breaker bar with 1/2 socket,
8mm open/box wrench,
19mm or 3/4" socket,
5mm hex wrench,
Steering wheel (or similar) puller,
Air impact wrench,
longer bolts for the puller (may be required)
Remove four bolts to the starter idler cover. Remove the small idler gear and set aside with the cover.
Remove the left case cover. Loosen the nine bolts in a criss-cross pattern so as to avoid warping the cover. Once all are loose, remove them. The bolt farthest to the left is securing the Raptor's ground wire, so disconnecting the battery is also recommended. You may have to rock the cover back and forth to get it loose. Try not to pry as this can easily damage the mating surfaces. Carefully move the bottom oil line out of the way. This is a solid line so bending it to far or with to much force will damage it.
Remove all the dowels and set aside. Remove the flywheel. While holding with a strap wrench, loosen the nut 1 in. This is where an impact wrench comes in handy! Otherwise, a breaker bar will suffice. You may have to have a helper standing on the rear brake and also have the bike in gear….This nut is TIGHT! Once loose, remove the washer and loosely replace the nut (recommended) so when you pop the flywheel off, the nut will stop it from flying forward.
Pull the Flywheel. Now its time to set your puller up. You may have to get some longer bolts for the puller so they will reach (depends on the one you use). Line everything up and make sure you are straight, it helps. Now apply some torque on the center bolt and tap on the end of the puller with a hammer until the flywheel "pops". It may take a while but it will eventually break free…Don't give up!
Remove the woodruff (flywheel) key and set it with the other parts. Pull the 52 tooth (large gear behind the flywheel) idler gear off the shaft. If you have a 2001, remove the needle bearing and set aside. You will not reuse this bearing if you purchased a kit. The gear we sent to you is ready to go with a pressed in brass bushing. Check the bearing surface for wear and pitting and replace if worn.
Remove the one-way from the flywheel. Hold the flywheel on a stable surface with a shop towel or something similar. Loosen the bolts in a criss-cross pattern to avoid warping the flywheel. After all the bolts are out, the one-way will be a little tight, so you may need to press it off from the inside of the flywheel.
Clean out the flywheel. Use rubbing alcohol and clean all the grease and debris from the inside and outside of the flywheel.
Install the one way. Line up the bolt holes. Prepare the bolts by putting some red locktite on each and snugging the new bolts by hand. Tighten the bolts in a criss-cross fashion to 11 ft/lbs or 16 N/m. This is critical, you must torque these bolts correctly and evenly!
Clean the old gasket material from the case and the cover. Cover the hole (case side) that is open to the transmission to stop debris from entering. Clean both surface carefully and wipe clean with rubbing alcohol. Also clean the shaft surface and make sure all debris is removed. If you removed the wiring harness gasket, put sealant on one side and replace.
Put engine oil/lube on the shaft.
Install the idler gear onto the shaft. Now place the woodruff key in the slot. Now slide the one-way/flywheel assembly over the shaft. Turn it to make sure the woodruff key is where it should be and that it rotates smoothly.
Install the gear on the one-way/flywheel assembly. While this is not required with a stock unit, the L&A needs to be installed slightly different. Turn the gear clockwise while inserting the hub of the gear into the one-way opening. Now try and turn the gear counter-clockwise, it should engage (not turn). If this is the case, you have succeeded!
When you are satisfied the assembly is correct, place the washer and flywheel nut on the shaft. Grab your strap wrench and place it on the flywheel and tighten the nut to 110 ft/lbs or 150 N/m. Once again, you may need a helper to hold the rear brake and the bike may need to be in gear. Make sure everything is well lubricated. Place the dowels in the case.
Remove the shop towel you were using to stop debris, place your case gasket over the dowels. You may use some gasket spray (slightly adhesive) to hold the gasket if you like. I usually don't need to as the dowels hold it in place fairly well. Place the case cover onto the dowels and tap lightly; possibly rocking it slightly to position it. If it become very hard or is not aligning properly, remove and try again. Replace the idler gear near the starter, replace the gasket (small size) and the cover. Put your ground wire in position, replace all the bolts and tighten to 7.2 ft/lbs or 10 N/m. Use a criss-cross pattern for tightening a before. Move your oil line into place and reattach.
As a recommendation, replace your drain plug with a magnetic one. Fill the bike up with oil and ride it for 15 minutes or so. Drain your oil (clean your magnetic plug off) and replace the filter. Fill it up with oil and you are ready to go!