Ford 1999 Wagon-Econoline Owner's Manual page 76

Seating and safety restraints
2. Pull the seat latch handle, then
pull the seat toward the right side of
the vehicle to disengage four pins
from the floor mount.
3. Remove the seat.
To install the seats:
Check to see that the seat and seatback is latched securely in
position. Keep floor area free of objects that would prevent
proper seat engagement. Never attempt to adjust the seat while the
vehicle is in motion.
1. Position the seat to the floor
mount.
2. Engage the four pins into the
floor mount hole and push the seat
toward the left side of the vehicle to
fully engage.
3. Pull the seat latch handle downward to lock the seat in position.
4. Make sure the safety belt is not twisted, then insert the seat belt
tongue into detachable anchor until you hear a "click" and feel the latch
engage.
SAFETY RESTRAINTS
Safety restraints precautions
Always drive and ride with your seatback upright and the lap
belt snug and low across the hips.
To prevent the risk of injury, make sure children sit where they
can be properly restrained.
76