Transmission oil change.

It shouldn't be a problem. The transmission fluid in a CVT is for lubrication only. There is no hydraulic pump, no torque converter, and there are no solenoid controlled gears to shift. I would however check that the fill plug (the upper one) isn't frozen on before taking out the drain plug. Use the Toyota brand transmission fluid.

 

Yeah Owner's Manual strongly recommends Toyota ATF WS fluid, and cautions that using any alternate may cause damage. That's regularly debated here, but I wouldn't gamble.

You will need 4 quarts (or liters), and will probable use about 3.5. Also good to replace the drain and fill bolt washers. The dealership parts departments should have both items. Up here the fluid is just over $9 (CDN) per liter, and the washers were around $3.80 apiece (exhorbitant):

1. Raise and level the car. (Level car is mandatory to get the fill level right.)
2.. Remove fill bolt (Just as a precaution, you don't want to drain the fluid, then find the fill bolt stuck).
3.. Remove drain bolt, with a catch pan of some sort under.
4. Reinstall drain bolt with a replacement washer, torque to 29 ft/lb.
5. Add new fluid through the fill hole, till it starts coming back out. (I found a funnel with hose extension from above very simple (keep hose OD 5/8" or less, to fit fill hole with a little spare). Good to have an assistant pouring. Go slow after 3 quarts.)
5. Install fill bolt with replacement washer, same torque.

Notes:

a) Both drain and fill bolts are socket-head-cap-screw type, with a 10mm hex recess. You need a 10mm Allen Key style socket. Stanley for one makes a set.
b) Recycle any left-over fluid. Toyota recommends to only use fluid from freshly opened bottles.