Having no history with the car, I'm unsure when/if the timing belt was replaced. It's due at 90,000 miles or 6 years, both of which have past. The alternator belt doesn't inspire much confidence there either, looking very much like it's the belt fitted 11 years ago at the factory, judging by it's state.
Parts ordered from Discount MG Rover Spares arrived now ready to fit.
Step 1. Loosen the alternator and remove the aux belt. The nuts took a bit of effort to undo. I could only use a spanner as access is tight so couldn't get much leverage. The belt is tensionned by a small 10mm bolt best accessed from underneath. Three alternator mounting bolts loosened and the tensionner bolt undone and the belt can be slipped off the pulleys easily.
Step 2. Undo the crankshaft bolt. Probably the hardest part of the whole process as the crankshaft bolt is ridiculously tight (spec. says 205Nm). I tried my electric impact wrench, rated for 440Nm, it didn't budge. 5th Gear selected, handbrake on and an assistant standing on the brakes still couldn't undo it. I found if I replaced the road wheel and lowered the car to the ground, that I could fit a bar through the alloy to the bolt using a universal bolt. Broke the universal joint and the bolt did not budge. Finally, I went for the unorthodox method of wedging a bar against the suspension mount and flicking the starter motor. 4 attempts on the starter and the bolt came undone.
Step 3. Remove the covers.
Step 4. Relax the tensionner using an allen key and remove the belt.