Get a firm grip on the pulley with both hands, with your thumbs on the outside of the pulley, and your fingers on the inside. Squeeze your fingers toward your palms as hard as you can, while at the same time turning the pulley face a bit toward your left. It'll slide down and twist as you pull it in... and the further it goes, the harder it gets to make it go any further, so hold it with one hand and cram the belt down with the other to lock it in place so you don't end up having to start over, then go back to using both hands to pull the pulley face in a bit more, then rinse and repeat. After 3 or 4 tries at doing that, you'll have your belt as far as you can get it, and you can then pull it off the variator pulley, then slip it off the clutch pulley.
Do the same to get the new belt on, put it on the clutch pulley first, pull the pulley face in, slide the belt down, then once you've got slack, slip it on the variator pulley.
I've made a little block of wood with the same shape as the sheaves that I jam in between the clutch sheaves once I've got them spread apart, that way I don't have to spread them apart a second time to get the new belt on.