Here you see the drive unit and its belt.
There are a few things to do before getting the belt out from under that
black encoder disk.
For starters, you must remove the drive assembly from the X3
shell. Four gold screws hold
down the drive frame. The photo below shows an enlargement of one of
Notice the black bump that pokes through each mounting
tab. These can help you position the frame when reinstalling it.
A magnetic screwdriver can help you re-insert the screws.