I've done this a few times...
Unbolt the upper front crossmember and the two through nuts for the radiator pads. You don't need to remove it, just enough room to push the radiator forward about 1/2" to clear the studs.
A thin flat something is also helpful sometimes - I have a longish 1/4" flat screwdriver that comes in handy for this. Once you get one side up, you can "rock" it off the pilot through the middle of the pully.
In rare cases, it can also be helpful to unbolt the fan blade from the fan clutch - but try it without doing that first, since it has a tendency to get in the way.
Two points to keep in mind...
1) I find it helpful to brush a little never-seez on the pilot of the hub, but NOT on the studs. That makes it easier to take it off next time.
2) It is theoretically possible to replace the studs with, I believe, 1/4"-20 bolts (short ones!) but I haven't actually done this yet, so I can't give you any pointers. Me being me, I'd use brass bolts, since that eliminates the worry about galling or seizure (same reason I use brass or bronze on exhaust goodies.)
5-90
