On a related note (trust me) he needs to take all the linkage , swingarm , wheel , steering head bearings out and clean and regrease/repack them all as well , along with something that is usually overlooked ...... Take the chain adjuster bolts out and flush out the swingarm with WD-40 , then on the swingarm side of the weld where the wheel goes , on the bottom of the swingarm , drill a 1/4" hole , so if/when the bike is in any water , the swingarm will drain ..... I don't know how many times I have seen the adjuster bolts rusted in place and end up stripping out the threads and then the swingarm becomes a project trying to get the rusted bolt out , then re-tapping the threads or having to install Heli-Coils , so put in the drain hole now , before it becomes a problem later
Drill the hole where indicated on the underside center just behind the weld (don't drill at the weld or you will miss the inside of the swingarm and drill into the plate for the bolt , which will not allow it to drain)