Yup - Mk1 headlight bulbs are a PITA, but not the worst. I used to take wheel off ( check brakes at same time ) and peel under-arch liner back, always found nearside bulb easier because i am right handed ( and the screenwash reservoir gets in the way on drivers side ) - when I did a lot of miles in MK1's, many in the dark, I used to change both bulbs every year on a nice warm, dry summers day. The plastic liner is a lot more flexible in summer, can be tough and even crack on a cold day. If proper quality H4 LED bulbs been available back then I would have bought them in a heartbeat and swapped them when I sold the car. You can just about get access if you turn front wheels fully to make more room behind headlight, but I always found taking wheel of a lot better.
If you do them yourself remember that of the 3 location lugs on an H4 bulb ( about 120 degree spacing) the widest one faces upwards when they are installed, makes it easier as space and visibility is real tight around the bulb.