I just did the same job recently. On mine I just used a floor jack with a small block of wood under the oil pan. You'll need to push and slide the engine slightly to get the mounts in place, but it *shouldn't* be that difficult.
As for the shouldn't be that difficult statement. The reason I was replacing mine was for two reasons. First, the rubber mounts were way beyond shot. The rubber was separating from the metal base and breaking down. Second was that the frame mount on the driver's side was broken where it bolts to the cross member and the weight of the engine was pushing the mount onto the steering shaft. This made for some slightly stiffer steering. Bill M (who else) gave me a set of frame mounts so this was going to be an easy replacement. Right? Wrong. It turned out that both my original frame mounts were broken, and both of the mounts Bill gave me were also broken. Not a hard thing to fix, just some welding and grinding on the mounts before I could install them but still, not as easy as it should have been.
So with all that said, I would definitely clean and inspect your mounts while you have things apart. Look closely at the flanges of the mounts where they bolt to the cross member. Mine were broken right in the crease and very hard to see.