How do you install a drive belt on a peace sports 50cc scooter?

Remove the CVT cover, be careful with fuel drain line and cables, and make sure you put them back where they were.

Take off the 17mm nut from the front variator and slide off the outer pulley.

you will be able to remove the belt. Squeeze the rear clutch pulley to make it wider and drop in the belt, hold tension on the belt so that the pully does not go back in again, put the belt onto the front shaft, slide the outer pulley back on exactly as it came off and snug the nut, squeeze the belt to get slack and then tighten the variator nut all the way.

Carefully put the CVT cover back in place. DO NOT over-tighten the 8mm bolts; they will strip.