MX5 Mk2 Wing mirror disassembly

[12 element]

Is it possible to remove the base part completely from a mk2 wing mirror?
The mirror I have is damaged on the part that surrounds the glass so I bought a replacement mirror but there seems to be damage on the metal part that bolts to the door.
I'd guess that it was damaged by someone drilling out the screws when removing the mirror.
I've removed all the screws in the mirror but there seems to be hollow tube that passed through the mirror hinge that is held in place with a circlip that I can't figure out how to remove!

Any advice welcome!

Thanks

[12 element]

Just for anyone else in the same situation as me this is how the two parts are held together. I broke the old one apart when I was taking it off. You'd need to apply a lot of force to compress this spring enough to get the circlip off so I didn't bother changing it over!

[12 element]

Here's the new mirror:

Happy enough with how the paint came out. Thinking about doing the bumper and drivers wing as they were painted before and the paint match is awful!