If you've got the manual, use it. I just changed the oil in my CRF450 forks over the weekend, it was actually pretty easy. The only manual I have is the owners manual that came with the bike and it had all the info I needed. One thing that's different between these and KYB's, you don't measure the fluid by how close it comes to the top of the fork, instead you measure by how much you put into the fork....so a Ratio Rite or some other type of measuring cup is mandatory!