Ed the SCV
Go south, east three times, south, then east twice. Go north four times, east, south twice, east, south three times, west, then south. Talk to the SCV here, hell give you a missile launcher. Then, you reverse: north, east, north three times, west, north twice. Then go west and south. From here, destroy the bush to your left. Go west five times, north twice, east, and then follow this path until you get to the Valkyrie. Go back along that path. Go back to the entrance of the fiery place, where you will find a rock to the north and the south. Destroy the southern rock and follow the path to the teleporter. Use the teleporter and destroy R2D2! Hes not difficult, he moves slow and has to get up close to attack you. Good luck!