Raz
The first one I did, I used wood shims/blocks and after unbolting the two motor mounts, gently pried up with a crowbar along the edge of the mounts to just get the weight off the loosened bolts. They come out easily after that. Leave the genny mounts as is until the motor mounts are done. Then do the same with them. Don't know which mounts are bad on yours, but definitely do the worst ones first. The second one I did, unbolted everything and snatched from the big hook on the top with the four post lift and did all at once. Like Jim said, think through your plan first. Don't believe I would jack on the center of the oil pan. Good Luck!
David