How Do I Non Destructively Remove This?

[Curmudgeon10]

I need to cleanout my shower drain, which is covered by the whatever-it-is-named in the picture. How do I remove this and reinstall without doing any damage to the shower?

 

[nealtw]

[ame]https://www.youtube.com/watch?v=QcDXzcZSwLw[/ame]

 

[Curmudgeon10]

Thanks very much.