I've done them before on other folks rigs, using an engine hoist to help pickup or move around the weight to get holes lines up or to move stuff up out of the way.. another way I've done it before, is to use a floor jack either on the oil pan (with a board between them) to do similar as the hoist.. or use a floor jack with a 2x4 going from the jack up to the bottom of each mount @ the block... and use that to tilt/lift the engine a bit to swap them out.. usually doing it that way will cause a bit more of a struggle as you'll have to work around the board being there.. and doesn't give much wiggle room at all.. Got new HD mounts for mine, and have been putting it off for the same reason, not wanting to struggle with it.. but has also been the weather keeping me from messing with it.. was too cold... and now it's way too hot.. lol.. so kind of putting mine off for a bit as I don't currently need the new ones in there..