How do you lower the spare tire on a 2002 ford E350?

If equipped with spare tire lock, attach key to crank.

Open rear cargo doors.

If a cover plate covers the hold for the spare tire winch, remove the cover plate.

Insert crank into hole until it engages the winch, then turn counterclockwise.

If it won't turn:

The winch is broken (usually caused by corrosion.) Cut the cable holding the spare tire up to get the tire out of the way, then install a new spare tire winch.