Thanks for the reply, that saves a lot of hassle...Ive been down that road...it didn't work, as you essentially need 2 holes, where 1 is at the moment . You cant add a another hole further round as your spacing will be out.
Also they are seriously hardened steel and will probably laugh at a standard hss drill bit I should think.
Best option is to buy a cheap set of xc range shifters and swap them out.