There really isn't a way I know of doing that, but if you want to open it up its shouldn't be too hard.
Usually there is a jumper on the motherboard that if you pull it off for a few seconds and then put it back on it should clear the memory. You usually have to wait about 5 seconds or so to allow the capacitors and inductors a chance to power down.
If you don't have the manual for it and the motherboard itself is not self explanatory then you could just try guessing. As long as the computer is off and you always put them back in the same spot, then you shouldn't be able to mess it up.
Hope this helped