not too sure which one you mean, but i usually grip the roll pin in some mole grips, that just nips them up slightly and makes them easier to get started.
don't know if you have room for that where you're working?
Have you tried moving the shaft as though engaging a gear. This allows for more access to the holes. It is possible in situ as I replaced the oil seal to the shaft on my 33 a number years ago (I still have the special tool for inserting the seal if anyone wants to borrow it), I was able to get the roll pin started using a small hammer, surprisingly called a pin hammer, I then used a small G-clamp to press the roll pin in.
John, its much easier than you think mate.
Due to my "gentle" driving, I snapped that pin quite a few times till now.
Just push it up, and move it about. It will come off the selector of the gearbox very easily. Then you can drill your hole and put a pin instead of that square safety lock they use.
.... if we are talking about the same thing that is ...
thats a good idea actually! i did get in a bit by squashing one end a bit with the mole grips. if i had a clamp it might just work. thanks for all the advice anyway. i have come to the conclusion i will never make it as a mechanic lol!