madgooner :
Is it possible to either replace the leads or cut off the ones i dont need?
Not sure of your intention with the replace the leads part of the question, but to cut off and remove the unused leads of course you can do that.
However you'd have to decide if this is a one way ticket [Allowing no future use for a hardware upgrade] for you, or a round trip ticket, [Being able to restore the leads for future use].
In a one way ticket senario you could remove the leads back to the solder point! See Note:!!!
Note: Danger !!! Power Supplies are still voltage charged through the capacitors even after being unplugged, you will need to ground and remove the stored charge!!!
The round trip ticket senario is cut, label, and insulate the wires about 3" outside the P/S, so if needed later, You could solder them back together and insulate them [Preferably with heat shrink wrap], for continued use.
Personally I'd take the round trip, if it was absolutely necessary for your situation, but you do need to realize once you cut the wires!, Your power supply warranty is gone!