Need help urgently, doing the job right now, glow plugs

Sorry for not looking but...

Is there a trick or some kind of way to stop the top nut from turning while trying to undo it (the one with the wire) from turning?

Any help would be grateful thanks

I might have a total memory lapse here but when I last did mine I removed the little nuts on top of the glow plugs, moved the wire out of the way and then got a larger socket, deep 12mm (can't remember) and slid it over the glow plugs and then undid them. I soaked them in lots of WD40 before I did it and they came out fine.

What bit is spinning??

-Wills

It was the little nut at the top (holding down the wire) that was twisting, anyway its sorted now, i uses a very small set of grips to hold it, i noticed when i took the first one off, there must be a tool to hold it in place while you are undoing it, there are cut edges on the thing to put a very thin spanner on it to hold it in place while yo undo the nut, but i couldn't find anything thin or small enough to use!!

Just as a follow up, i would like to add, it has made a very big difference in how my RR now starts up from cold first thing, its instant, so if you having problems with a longish start, this seems to be a good easy and cheapish way to at least discount one of your problems, its an easy job to do, will take about 1 1/2 hours to do from start to finish, and even if that's not the problem at least you have discounted it, but get good glow plugs though, it will pay in the end, trust me on this one i got a good set of "WELLMAN" HEATER GLOW PLUGS ok cost more, but last a lot longer and you will have a lot less grief with things going wrong on them, there a premium brand, will cost £30 for a set, last a lot longer and you will only have to do the job once!!!