waviness old pipe riser in floor ? (photo)

[Linus_E]

Hello.
The air-to-air heat pump has been installed and all the old radiators have been removed. How do I now cover up all the holes in the floors in the nicest and simplest way?

For 3 of them, I can replace a piece of the floor, but in the living room, there are 3 that can't be replaced without taking up the entire floor. So tips are more than welcome...

Best regards, Linus