This mission begins automatically after completing Precipice of War. This quest is part of the Railroad missions.

After obtaining the quest from Deacon, get into Vertibird, and Tinker Tom will fly you and Deacon to the Prydwen. Once you land on the Prydwen, you can try to stealth you way inside, or go in guns blazing. Make your way past the Brotherhood soldiers, by killing them or sneaking past, then head into the Prydwen Command Deck, then up the ladder to the Prydwen Main Deck.

Head up the stairs to the top level, and you'll find three gas bag valve locations where you need to place the explosives. After planting the three explosives, return to the Prydwen Command Deck, and then out to the Prydwen Flight Deck. Get back on the Vertibird where Tinker Tom is waiting, and once you're on board, he'll fly you away from the Prydwen.

As you are leaving, you'll encounter some hostile Brotherhood soldiers on the ground. Use the Vertibird Minigun to deal with some of them. Once you are out of the blast range, Tinker Tom detonates the explosives and destroys the Prydwen, this starts the next Railroad quest, The Nuclear Option (The Railroad).

Once Tinker Tom lands the Vertibird, deal with some remaining Brotherhood soldiers, then exit the Vertibird and Tinker Tom will fly away. Return to Railroad HQ and talk with Desdemona to complete the quest.