NB pot might work. Though there is a row of pins near the core. Guess it depends on the size of the base. There is that thread about making a NB pot from the copper insert of the Intel stock coolers. That might be small enough.
From the looks of it, the core is probably powered from a linear regulator. If it's a fixed one, just pop it off and get an adjustable one. If it's adjustable regulator, find the resistors that set the adj pin.