ok I got it off and checked the voltage and found it to be 12 volt at plug with engine and A/C on and no engagement of clutch so I am going for a new compressor. I am relieved I now know where the fault lies.
The instructions to remove this plug as given to me by Schmiedmann was
"The plug connector is just a push fit,
There is a minute tab inside the plug housing to ensure the connector stays in position, and this is confirmed but the audible “click” when pushing the plug home.Removal is firm but controlled pull, and maybe a gentle separation with a small flat bladed screwdriver."
I used a long flat bladed small thin screwdriver and was able to lever it out with that.
Here are links to pictures showing the BMW X5 compressor connector socket
https://www.dropbox.com/s/mcfg2kckt8...14.03.jpg?dl=0
https://www.dropbox.com/s/l0wvzgl8bh...13.50.jpg?dl=0
https://www.dropbox.com/s/4hlxn540cu...19.36.jpg?dl=0
Ok so lets just add a little more to this story to show the sorry state of BMW dealers. I live in Yangon, Myanmar. When I bought this car there were no dealers so has always been up to me to import parts and fix it.
I went to the dealer thinking I would get them to fix this. They quoted me US $1650 for the compressor part alone and then told me
if I brought in parts from somewhere else they would not fit them for me. Their labour rate is $75 per hour which I am not too upset about. If I ordered the part from them it would take 4 to 6 weeks to get here too.
So I can get the compressor aftermarket (Nissen) from Schmiedmann.com Denmark for under $400 US including postage. Will take it to another shop I know and do it with them. Going to save myself a months wages on this one job alone.
Hope this helps someone else too.