With AAMs and possibly sophisticated AGMs on board, you could usefully delete two of the guns.
The inboard guns are mounted further forward and feed from the forward pair of side-by-side magazines, while the outboard guns are mounted further back and feed from the aft magazine pair, so:
Option 1: Delete the inboard pair of guns, replace them with an internal link collector box (half as many links to catch) and delete the Sabrinas, thereby reducing drag. Use the space freed up by the removal of the forward magazines and the inner gun barrels for more avionics. You could replace the Sabrinas by fairings carrying electronic antennas.
Option 2: Remove the inboard gun on one side and the outboard gun on the other, then double the size of their magazines. In a close support situation, the increased combat persistance might be worth more than the reduction in instantaneous firepower, and in any case, 2 x 30mm is still equivalent to most jet fighters of the era. You'll probably have to keep the Sabrinas because you've still got the same number of links to catch.
IIRC, the Central Fighter Establishment recommended reducing the guns to two, stretching the forward fuselage slightly and adding an extra fuel tank. Not sure if that would be possible as a refit, but it's worth thinking about.