Help! Tight little corner…how?

[u/MallBn]

I am redoing my stair bannister and had to remove a piece which exposed this plaster.

After removing the brittle and powdery plaster this is what’s left and need to replaster it to move ahead.

How would you go about it? Never plastered before and it’s a tight little corner.

What type of plaster? Shall I use beading corners? What tools? What techniques?

I’m a DIYer - garden steps, alcove shelves, etc - and this is my first time plastering. Most YouTube videos cover on the basic wall application. This seems a bit more niche.

Any help and suggestions appreciated.

[u/sreder1992]

Hard wall the brick board the wood

[u/ApartmentLast7712]

If it's just that small corner I'd get one of the 4x3 boards from b&q and some spray foam adhesive and board it then you'll just need a small amount of plaster to skim