Right, it's the 20VT manifolds that crack, not the 20V ones.
And my experience of changing a radiator on a 20VT with aircon isn't great. The 16V may be different, but on a 20VT w/ aircon it goes like:
Remove the undertray - the radiator has to come out the bottom as the aircon pipes are in the way at the top.
Drain the cooling system by pulling the bottom hose off the radiator. Remove the other hoses too.
Remove the fans from the radiator. Thease can come out the top.
Remove the 2 bolts at the top of the radiator.
Then to actually get the rad out, the easiest way I found was to unbolt the 4 bolts that hold its supporting strut on. You'll see what I mean when you're underneath! The rad and supporting strut come out together. To actually get it out, you need to jack the front of the car up.
The rad fits into the strut with 2 rubber grommets, which were very stiff on my car.
Replace the old rad with the new one, and reverse the process to refit.
Fill the cooling system, and bleed it using the bleed points on the radiator, thermostat and on the front of the block.
Then run the engine til it's hot, and refill the coolant if needed.
Like I say, that's for the 20VT - the 16V might be completely different (and much easier!)
H