Directly from a 98 Ranger Owners Manual
Shifting between 4X4 HIGH (4WD
high) and 4X4 LOW (4WD
1. Bring the vehicle to a stop.
2. Depress the brake.
3. Place the gearshift in N (Neutral) (automatic transmission) or depress
the clutch (manual transmission).
4. Move the 4WD
control to the 4X4 HIGH or 4X4 LOW position.