You can do the "X" in lots of different spots .
It will go faster if you have 2 people .One on the smart end & one on the dumb end.
I am 99% sure that Motor mounts are universal ,bolting them up is a BIG PITA.
If I remember right a Ball swivel socket is a life saver in this job.
Also some good magnets , to retrieve the nuts & bolts .
Here's a couple of trix. . .
If you take some paper & put it over the bolt then stick it in the socket it will hold it in places & still let you get your socket back.
If your swivel socket is loose a little electrical tape will hold it from flopping around.
It most likely easiest to drop the bolt down thru & nut it from underneath. this way there are no clearance issues with the "cup " on the Motor side of the mount.
Please let me know what you find out on the misalignment part.