Timing belt tensioner issues

I’ve just suffered through replacing the timing belt, water pump and auxiliary belt on my 2002 TF. I’m just trying to put the new tensioner on now but seem to be having issues. In the workshop manual it says to rotate the tensioner anti clockwise with a 6mm Allen key. I’m doing this but this is making the index wire that catches over the bolt rotate round so the open end of the wire is now stopped on the underside of the bolt. The manual says the tensioner pointer must approach the index wire from above but it can’t physically do this if I’m turning it anti clockwise.

Is there something really really obvious that I’m missing? It’s been a very long day and I’m missing most of the skin off my knuckles and wrists. Had I known how awful a job this would be I think I’d have just stumped up the cash to let someone else do it.

Maybe this might help

Stick with it mate I did mine last year and was pulling my hair out, then it all fell into place and I wondered what I was fussing about. Check out the vid and there is at least one other on youtube, a picture is worth a 1000 words but a vid is priceless.
Good Luck

Found the vid but cant seem to copy a link, so Youtube search for MGTF cambelt change and pick the Rimmers one which includes the head gasket, if it opens at the start fast forward to 25m 15s in and you will get a clear picture and explanation.