First of all, to save time, get the items. Grab a cabbage from Edgeville Monastery near the Black Knights' Fortress or at the cabbage patch in the farm south of Falador (cabbage taken from Draynor Manor will not work; you will find out why during the quest), buy an iron chainbody from Wayne's Chains in Falador, and buy a bronze med helm from Peksa in Barbarian Village (or get one in the backroom of Draynor Manor). If your Smithing level is high enough (3 for the bronze medium helmet, and 26 for the iron chainbody), you can just smith the chain and the helmet. If not, you'll have to buy them from the shops listed above or buy them from the Grand Exchange.