I'm going to be doing this as well. While reading up and searching for the needed tools, I found this How-To write up:
Haven't read through it all yet, but there appears to be plenty of photos.
As I need to also replace the driver's side valve cover gasket, I'll likely postpone that job to coincide with the motor mount replacement.
By the way, what's the deal with so many people wanting to use floor ramps instead of jack stands? Especially when doing under the vehicle work on difficult to reach stuff? I'd rather pop the wheels off and get them out of my way. Floor ramps, while convenient, have always been a huge space-hog of a tool in my experiences. I pretty much quit using them back in the early '90s, unless I NEED to keep the wheels/suspension supported, like when doing an alignment.
I haven't used that particular Harbor Freight tool before. From the photo and previous experience with their tools, I'd be a little leery of the steel support foot (triangles at each end) cutting through the rubber/plastic foot and landing on the fender frame directly, messing up the paint and likely denting it.
I would also be hesitant to risk my hands/arms to being crushed/pinned under the engine should one of the welds break on the threaded lifting rods. I've already experienced a similar type item (thin welded support hook) breaking and damaging what I was working on. Fortunately I wasn't between two hard spots at the time and still have all of my fingers... for now.
Given the simplicity of the tool, I would be inclined to use a 4x4 piece of wood for a cross brace and create a similar jig to hold the engine up.
If you do buy their tool, I recommend swapping out the threaded hoisting rods for high quality, grade 8 or better, ones. And, if nothing else, put something additional under the engine/between the frame just in case! Better to destroy the whole vehicle than crush your hand or arm!
I have a friend who lost an index finger when we were doing the same thing back in our young 20's. It changes your life. Permanently.