Andy has it right. The job is a b***h. I have done it loads of times, heating the rubbers even with hot water (it does not go in the engine!) and on reinstallation use WD40 or even copper slip to lube the rubbers. Don’t do it in a freezing cold garage either – the cold does make a difference.
The cables are the biggest ‘B’ and I have not found an easy way round. I disconnect them when the carbs are free of the rubber mounts as you can get to the connections a little easier and likewise putting them back on. Problem is holding the carbs while doing it so – no simple solution that I know I am afraid