Home repairs.

For this, you need to take  C profile.Measure the appropriate length and attach to the wall by  plug and shrupom.

Then take plasterboard and accurately cut out using  the construction  knife, shape oval.

Then, fasten the plastboard on C profile.Now, it remains attach  the plasterboard to the profile.And using a putty align all irregularities.

That's all. thank you, good luck.