repair this corner

[Stamford]

So I had a damp problem, take all the plaster out they said, it'll be fun they said....
OK I've removed the damaged plaster, the problem was under the window, but it has risen either side, tanking and renovating plaster, plus some work outside.
How do I repair the corner tho? There's a metal bead still in place on the upper part, should I just attach another bead and use that as a guide?

 

[PrenticeBoyofDerry]

Personally I would rip out the full length of angle bead and repair and replace the total length.

 

[chappers]

yeah rip it out and all the plaster in the reveal and a few inches along the wall and reset a new bead, then float and set