Tips on replacing HWH kick-down jacks
There are 4 bolts, two at the front, hidden under the kick-down hinge. Swing the jack down and use a ratchet and extension to remove. Remove these first, install last. Do not tighten until you have the jack aligned (frame clearance, etc).
Remove the tie-downs holding the electric and hose in place first. Easier to disconnect and reconnect after dropping the jack.
Don't worry about bleeding as the jacks are self-bleeding. Just cycle a couple of times and you should be in business.
HWH has manuals on-line but the term Technical comes into play.
Not hard, just helps to use a floor jack to raise and lower the jacks.