CJJB, I have not removed the alternator on my 85 +8, but I popped out to the garage to have a look. I would take a pic but I am not up for posting my pics other than directly here, don't fancy using a hosting site...My forum ID kinda hints at my mindset...
To get back to the point, on my +8 I can see the supporting bracket for the alternator looks like it unbolts with two bolts visible and looking reasonably accessible from above, though I suspect there will be another one at least below, perhaps accessible with a socket and extension from out front of the alternator... Happy to look on the underside tomorrow, if that might help, assuming we might have the same set-up..?
