After you destroy all of the mines, disable the FRT by using your lasers until its shields are down and then switch to Ion cannons and disable it. Make sure you have all of your weapons set to dual fire. After the FRT is disabled our "capture" SHU will arrive. After that has docked and captured the FRT, two Imperial SHUs and 2 Imperial TRNs will arrive, you have 8 torpedoes on board your Y-Wing, select them (dual salvo mode) and get in behind each of the Imperial ships and take them out with the torpedoes. Two torpedoes per ship is all that is needed and since you have eight and there are only four ships you can kill the all of the Imperial ships very quickly.