Changing rear indicator bulb

Can anyone tell me how to change the rear indicator bulb on an MGF? It seems I must remove the entire unit to replace one bulb.

You dont have to remove the entire unit. The lens stays where it is. From inside the boot you will see a plastic section that holds the various bulbs. this is held onto the rest of the unit by a couple of plastic catches. Once you have found them they only need gentle pressure and then the plastic section with the bulbs is easy to lift clear,  allowing acess to change any of the bulbs. When done, just reattach it

Your car may or may not have a black plastic cover inside the boot protecting the rear light. That cover is held on with 2 or 3 nuts, remove those, pull off the black plastic cover and all the light connections will be shown, the little orange bulb can just be seen before cover removal.

Ive spotted the original poster had also asked the question on another forum and has now managed to replace the bulb.