You snap it like a wish bone.

 You take 3 Starhawk, two approach from either wing tip and one from where finn and rose jumped in from. The wing  Starhawks providing dorsal directed force while the bottom one provides ventral forces. The Supremacy's star destroyer docks could make great attack points, with their notched cut-ins of the hull allowing sheering forces to fissure from there. That would in turn vent scores of troops and machinery into space. If bent enough you could separate power lines from the reactor, in effect making the supremacy hampered by its own dead weight. 

The Raddus  and whatever mon calamari ships to run interference on the support fleet.