This was in the AOA forums, forget who or where - sorry:
Ive worked it out.
I broke the tract between R468 and R469 and made another from R268 and U39
I now have ajustable VAGP, at the moment im at 1.6v
I think I can probably go upto about 2v with a 1k pot, although such a high voltage would be very dangerous indeed.
I think the best method will be to remove R289 completely and replace it with a 1500 - 2000 ohm pot, for stock voltage you want about 886 ohms, and more resistance = more voltage in this case.
The best potentiomiters to use are cermet pots like the one pictured below (UH23A - maplins code)
The advantage is that its a 22 turn pot, so you can get a very high resolution from it as there are 22 turns between 0 ohms and 1000, also it means its almost impossible to accidentally knock it (and its small enough to tape to your mobo when not in use)
Remember to insulate the other leg of the pot as its still live (i havent in this pic)