Then, this is the thread for you:
http://www.iceinspace.com.au/forum/s...ad.php?t=60667
My mod is the same, the difference was I used smaller gears, so they fit nicely inside, without machining of the worm gear covers, like in Luke Bellani's thread
However, you need to be careful of reduction - if you are not planning to change the controller, then the gear ratio must remain the same as original (not sure about your mount.. you can count the teeth on motor and worm and calculate this (you can forget about tthe transfer gear in the middle, it doesn't go into equation.. I went for 12/60 = 5, since the control software I am using is/was fully configurable).