JW411,
I thought the procedure to lower and lock the CLG on the ground required maintenance to partially lower it using the aircraft electric hydraulic pumps and the CLG selector valve in the RH wheel well, then deflate the strut, complete the extension and downlock, then reinflate the strut to the required pressure. Retraction on the ground was the reverse process. No jacking required? Never did it myself but saw the results of not following the AMM when PAL were retracting the CLG in preparation for a 2 engine ferry back to MNL with a failed N0.3 engine and they did not deflate the CLG strut before commencing retraction. The CLG retract actuator broke/bent and dumped all no. 3 hydraulics on the ground.
Happy New Year