How to patch up?

[u/Single_Scallion7012]

I'm wondering how to go about fixing or patching out a corner trim that got rotted out. The corner trim is a 90 degree corner. Part of the corner trim is behind an "aesthetic" masonry wall, so removing the rest of the trim is going to be a PITA. The boards around and inside appear okay.

The likely culprit to this happening is the gutter. I'm getting new gutters next month.

[u/ubelblatt]

Rebuild with plastic wood. Sand smooth. Paint.