I've done it on several different bike makes. The roller bearing is a straightforward install, but as Mr. Breeze said - you need to have the old, lower bearing assembly so youcan compare stack-height. You simply remove the upper and lower races from the steering head of the frame, remove the race from the tree, apply grease to the bottom race, lay the 18 or 19 1/4" ball bearings (I forget how many) adnd you measure the lower ball bearing assembly height. You go to the "new" tapered bearings box and you lay the rubber/seal (dust) washer down first, then the bottom race down 2nd, then the tapered bearing narow side up, and then the upper-bottom race (cup side down of course) and take a measurement. This difference is your shim/washer requirement. The washer will go on the stem first so your rubber dust washer is always up next to you tapered bearing's bottom end. All you are doing is making sure the steering stem is in the same height posiition as it's designer meant for it to be. You must have the right amount of threads att he top to hold the nut, they don't want to change geometry, and it's really a straight forward thing - no magic tools needed.
I will add only that if you have your stem powdercoated or painted - that bottom race and tapered bearing "will not" go over the stem. A trick I use is to put the stem in the freezer over night and the race/bearings slip right on.
Go for it.
Regards,
Gordon