From MopedWiki

Here it is the best way I know of to crack open a variator without dealer tools:

Click the image to see the full scale version

Reasons to crack a variator:

• to grease the balls
• Removing a variator ball
• Shaving the back plate
• Installing a performance variating plate
• Using an AV7 variator on an AV10 motor

--Elldawg99 22:37, 11 December 2007 (EST)

Alternately,

• you can just drill a couple screws into your workbench to line up with these holes here or use 2 x 3/8in upside down drill bits mounted in vertically in a vice, set those holes onto it, thus immobilizing the assembly.

• Then use some heat to loosen up the nut on the back plate and break it free with a long wrench (or use a spare set of handlebars for a lever).

• Once you break the nut free, use some big channel lock pliers to break free the back plate.

• also, I noticed that these screws here:

Had been locked in place with little dabs of weld. I had to clear out the slots with a flathead screwdriver and some firm but gentle hammer taps.

• I like this way better because there is much less chance of warping the variator with the vise.