Have two people place C wrenches on the riser main on opposite sides of each other.

Have the two people with C-wrenches apply light upward pressure to the riser main while the base clamp operator loosens the clamp.

Lift the pipe evenly, not exceeding the comfortable lifting height of either lifter. Re-secure the base clamp once the maximum lifting height has been reached.

Lower the C-wrenches and repeat this step until the pipe coupling reaches the base clamp.