Changing the Auto box isn't difficult if you've got some mechanical experience and the tools. I've had to change mine several times. It's a Vr but I dont think there is much difference. You need basic tools and a trolley jack at minimum. I'll probably miss a few tools but the basic list is
19mm spanner (box to block bolts)
14 & 15mm spanners (tailshaft to diff bolts)
Socket set for the guard at the end of gearbox and the mount itself.
17mm socket for torque converter to flexplate bolts
A spanner for the shifter to box connection
Spanner for the oil cooling lines
So basically a spanner set, socket set with a ratchet and breaker bar.
You will need to jack the car up a fair bit. Car ramps would probably do it.
I start with taking the tailshaft off (4 bolts at the diff), the guard over the tailshaft/ output shaft connection, and then the mount at the CV.
Then I undo the 19mm bolts at the bellhousing. One of these has the dip stick on it, the dipstick simply pulls out of the pan once the bolts off.
Then undo the shifter connection.
On the bottom of the gearbox at the bell housing there is the torque converter cover, this is a heavy piece of steel which has four bolts holding it on. You need to take this off.
Once this is off you will see the torque converter which has three bolts attaching it to the flex plate. I usually take these out using a breaker bar and a 17mm socket (pretty sure its 17). You will need to turn the motor twice to reach each bolt.
Then take the oil cooling lines off.
Next you need a trolley jack and a piece of wood to take the weight of the gearbox. I find that the near the front of the pan is a good spot to balance the box.
Once you've taken the weight undo the four bolts on the gearbox mount.
Now slide the jack slowly back and down at the same time so that the torque converter/gearbox comes off the motor.
Drop the jack down very slowly just enough so that you can get your hand on the top of the box. There is one large electrical connector on the top of the gearbox you need to unplug. There is also a small electrical connector towards the back of the gearbox you need to disconnect.
Now drop the box down and your done. Installation is reverse of the above. However lining the gearbox up to slide on smoothly is alot easier with two people.
I've probably missed a step somewhere in there so if someone sees anything please add it. If your keen on doing the swap yourself I'd recommend getting a gregorys manual for your car as it outlines the procedure in detail.