Pretty easy... get a drill that will go into the recess in the top (head)
of the bolt that is slightly larger than the diameter of the threaded part.
The head will fall off  when you reach the threads. Remove the CV joint.
Then drill a hole in the remaining dimple to fit your favorite thread
extractor and have at it.

Jim

On Sun, Dec 31, 2023 at 7:12 PM Rick Cooper <rick@webleaf.ca> wrote:

> Hi all,
>
> I've got a noisy CV joint and thought I would remove and repair it today.
> But I managed to round off one of the twelve 6mm Allen socket-head bolts so
> that I cannot break the last bolt free.  Unfortunately it is on the outside
> CV joint so it inaccessible by most tools.
>
> Has anyone had this experience and can offer any advice?  Am I stuck
> drilling out/off the head of the bolt?  And then how do I remove the shaft
> from the wheel assembly since it will be challenging, even with joint out
> of the way, to get a good hold on it with vice-grips?
>
> Thanks for any help.
>
> Rc
>