Valve Clearance

[RED BARON]

I intend to adjust the Shims in my 912 Engine because one valve is very Noisy.
I know to do this I must take off the Cam Carrier with care to hold the Buckets in place with Strong Magnets.
The problem is I have broken out the side of the Head of one of the 4 Pan Head Torx Bolts on one Bank by using a Hex Key.
Has anyone got an idea as to how to remove this Bolt so I can get the Housing off.
I now have a set of Torx Sockets.

[Marten]

I intend to adjust the Shims in my 912 Engine because one valve is very Noisy.
I know to do this I must take off the Cam Carrier with care to hold the Buckets in place with Strong Magnets.
The problem is I have broken out the side of the Head of one of the 4 Pan Head Torx Bolts on one Bank by using a Hex Key.
Has anyone got an idea as to how to remove this Bolt so I can get the Housing off.
I now have a set of Torx Sockets.

Hard to say what the best method is. It all depends on whicht bolt, how bad you messed up, how much access you have and the tools available