How to Separate portion of Mesh along a line?

[Hazmater]

I’m Trying to get this

to do this

[rigoletto]

You have to duplicate your selection and then:

[Magnavis]

There’s not really a clean way to do this with what you currently have. You could use V to rip the selected seam, and then separate the two halves, but realistically, if you want something like that, then you need to have a model with the topology to allow for it; Or, have a separate object for the part that hinges.

[Hazmater]

@Magnavis\rigoletto Ty this helps.