Are you talking about the bottom swivel nut here.....new ones having 3 bolts rather than rivets?
I seem to remember getting in with a 17 or 19mm combination spanner without too much problem.
John
A tip may be to put a jack under the wishbone to compress the suspension, so the joint moves away from the CV a little.
I've done one before and don't recall issues like yours.
John
Thanks for the pic!
The suspension does look to be on full droop there so my idea of a jack under the wishbone may give you better access (or not).
I'm sure I used a combination ring on the car I did....a Jetta I think - if there's such a thing?
I do rate Delphi stuff, haven't heard of the others. Keep up the good work, and happy New Year to you!
John