OK, I got it out and got the rubber boot off as well. The boot was tough to shift and I was worried about tearing the "tabs" that I pulled on. Make sure it goes back on properly, to keep the weather out.
3 screws matter. Top left screw (left as in the picture) holds everything in place. Top right adjusts (or aims, if you prefer) the headlamp, as does the bottom screw. Don't move these, or if you do ensure you set then as they were. There's a clip on the top-right screw that holds the lamp. And the bottom screw conceals a hole into which the lamp unit sits via a locating "prong".
It's the lowbeam that blew, the centre single-spade connector. The other connector is for the parking light. I changed that 10 years ago so it should be fine ;-)