Remove rusted R clip

[oldbutnotdead]

Citroen C5 rear strut. Mr Haynes (and a few Tiktok videos) all glibly show the clip coming out with modest force- not happening in this case!
I've tried hammering (the pin is bending), heat, penetrating fluids, pulling with leverage (the R is distorting/opening up).
I'm tempted to try drilling the thing out (have some all-purpose diamond tipped bits) but have a nasty suspicion that the pin will be harder than the strut mount body and i'll just wreck the body. Reports on frenchcarforum indicate that trying to drift the thing out tends to split the strut end.
Any other possible removal methods to explore?
Cheers...
PS Pic to follow

 

[oldbutnotdead]

HA! Got the little swine. Fortunately on my C5 the clip runs horizontally so access is ok. R clip is approx 3mm diameter, there was about 15mm of the pin end sticking out.
Take an M8 or M10 bolt, 80mm long is ideal (gets the bolt end level with the rear disc so you can proper hit it with the hammer).
Drill a 2.5mm dia hole 8mm deep in the threaded end, hole parallel with the length of the bolt.
Apply your drift so the end of the pin goes in the hole in the end of the bolt.
Hit the bolt-square as possible but it isn't critical cos the end of the pin can't bend.
Repeat until the end of the bolt is touching the strut.
Try wriggling the R end. If it is still solid make another drift but with a 4mm deep hole.
Apply as above, hit it.
Happy chap