H1B -> Family Based GC -> Changing employer?

[shinkansen]

I've been in US on H1B for 4yrs now and have my I-485 interview (marriage based) on July 26. How soon can I change employer (presuming that my interview gets approved?). If they stamp my passport, can I change employer the next day.... or do I need to wait until I have the GC in my hands?

 

[TheRealCanadian]

If they stamp my passport, can I change employer the next day.... or do I need to wait until I have the GC in my hands?

You can resign your position at any time. You can accept new employment at any time. You can start work at any time after your case is approved, but to fill out the I-9 at your new job you will need the stamp.

If your case is approved at interview, ask for the stamp.