well two weeks later, i finally got round to doing the job
i got my bulb from halfords for 8.99 - it was a 477 and the code WAS in the little book (i've seen a few posts on here that said it wasn't)
i got under the bonnet and removed the battery cover. after a couple of minutes trying, it became quite clear that i was never going to get my hands down the side of the battery, so i made the executive decision to remove the battery, and after i did that there was plenty space to access the back of the headlamp, and it was a very easy job.
probably took me about 30 minutes including removing and refitting the battery.
i did take some photo's whilst i was doing it, i'll post them on here when i get chance.
Any updates on the Pic's SD