Unscrew these two bolts with your 6mm Allen Socket.

Unhook this from the break and foot rest. This is your rear light. Very important that you do not break or forget to reinstall later!

Tuck the rear brake/footrest onto the tire, easiest and most time efficient thing to do an won't damage anything if you push the foot rest in

I lost one screw in the first picture but yours has two ( or it should have it anyways), hence the two circles