no need to drop the subframe at all, can get to it from above. cut the old boot up and remove the nut/bolt from the universal joint. now go inside the car & remove the dash under tray. At the base of the column you'll see the other half of the universal joint, undo and remove the nut/bolt here and see if you have enough clearance to release it from the rack, I'm pretty sure you wont but its worth a try!
If not, remove the lower half of the ign stalk surround and disconnect all the wiring plugs from the stalks & ign switch. Now undo the allen bolt you can see under the column into the metal ign switch surround, release the steering lock, grab the steering wheel and pull it towards you, the entire column will come out
Now you should be able to pull the UJ off the rack, swap the new boot on and refit the UJ to the rack and bolt it up. Secure the boot over the rack and go inside the car, repeat everything you did the opposite way round, and che ck the top half of the boot is fixed properly into the firewall if you can see it thru/past the carpet & insulation
