replacing machined bearings in hubs

[lph]

Hiya all, I have a wobbly rear wheel on my road bike that needs fixing.

Since I know very little about road bikes I took it to my LBS, who decided that the bearings were shot but "very hard to replace", i.e. non-standard. I checked on the wide and wonderful internet and found that I could easily order 10 of them for 15 dollars, or go down to my local enormous tool warehouse 2 miles away and get them there...

So now I have a wheel with the innards taken out, and brand-new cartridge bearings.

Are these hard to put correctly back in? I've overhauled Shimano cup-and-cone bearings many times, but never this type. I'll check Park Tool etc., but it would be handy to hear from anyone who's done this.