I also changed my ancillary drive belt (water pump, power steering pump, alternator) without removing the fan & radiator cowl, though I had to cut down one of my sockets to fit in the tight space and there was much swearing and grazing of knuckles going on. When I replaced the tensioner pulleys for the ancillary drive belt at a later date I removed the fan & cowl (which wasn’t without its problems :
viewtopic.php?f=2&t=33214) and the additional space this gave to work in made a huge difference.
I haven’t replaced my a/c compressor drive belt so I’m afraid I don’t how easy it would be to remove with the fan & cowl still in place but the Workshop Manual doesn’t say you need to remove them so it must be possible – you just need to take the ancillary drive belt off first.
Maybe you should see if you can get the fan off easily – and, if so, remove this and the cowl to make life easier? If you can’t get the fan off - well, it should be possible to change both belts anyway - it’s just more of a struggle.
Phil