How to repair damage to plaster on corner

[LukeT]

Hi,

Trying to determine the best way to repair damage to the plaster on  a hallway corner.

From what I understand, this can be filled with a plaster filler and then sanded back and painted over (I have a small tub of UniPro interior filler from another repair).

Will the metal piece underneath need to be replaced as it has bent?

Will I need to remove the damaged plaster up until where it has cracked and fill that entire area?

Thanks,

Luke