2010 Toyota 4Runner Owners Manual - Page 251

2-4. Using other driving systems Shifting between H4F and H4L Push the "UNLOCK" button and turn the four-wheel drive control switch to H4L or H4F. This can be done at any speed. The center differential lock indicator will turn on (H4L) or go off (H4F). CTH24AS017 2 When driving Shifting between H4L and L4L