Take a look at CDave's site....linked in the
'Every kdx rider should read...' thread stickied to the top of this forum.
Or...click
THIS to get there.
Click on 'tech tips' then 'general---specialty tools'.
He has a write up on a 'tool', how to make it and such. It's basically a long lever attached to the flywheel side. Piece 'o cake.
Several options exist. Some have had luck putting the engine in gear and using the rear brake. Some have used rags pinched between the clutch/drive gears. Be careful about using anything that applies force against gear faces and shafts. 'Don't' would probably be a good idea unless you are convinced that's your only option.
Air is the easiest choice. Not any problem with a 1/2" impact and 100+psi.
Maybe a good excuse for you to buy a new tool? That compressor you've been looking at? ;)
Take care using a compressor when it comes to putting the thing back together.
One hint of note if you're not familiar with this assembly. You would be doing yourself a huge favor to have a service manual for this job. Take care to
not misplace the washer that is placed under the basket. If you are not expecting it to be there you might miss it being stuck to the underside of the basket. It will drop off later someplace. Then on reass'y, you will have a problem.
Also note the orientation of the large circumference conical spring and seat that sit on the outside plate.
TORQUE those bolts in the hub!! Hamfist those and you will be spending a whole lot of money replacing parts that get broken.
Good Luck.