yeah its pretty straight forward. you screw in the cups, slide in the spindle slide of the crank arm and then tighten the other side. (those a really broad instructions but you get the point). I am running the race face x-type cranks and they are definitely smoother pedaling than isis cranks. i have ridden a pair of the shimano xt's with external BB and they feel good too.
i think you should be able to do it easily. they are pretty simple to get on.
Ive had a play with my XTs on it while waiting for my saints to turn up, and it looks like Ill have to space the drive side out quite a bit for the mrp plates to clear the swingarm, about 4-5mm more than is reccomended, IMO too much as it leaves too little axle for the LH crank to clamp to.
So has anybody actually tried this setup? and how did it go?