Have 1k of the fragments in inv, and the item you want to make into an override, then I think the left click option on the override-to-be is "Complete" or something.
Bandos/Armadyl Claws, Shield, Wand, and something else. You get the pieces when completing certain things, like taking down caravans, killing ambushers, etc.
Let me live, so when it's time to die, even the Reaper cries.