Depends. EVERY fixture is different.
There is NO way to tell with out a picture of the fixture.

ok, i'll get picture -- thanks

Just curious, why do you need to remove the fixture to paint? Mask it off with blue painters tape.

I will assume that you have already looked closely for any obvious attachment devices showing (screws, nuts etc.). Often there is a glass bowl covering the face of the fixture with no obvious means of removal. If that's the case, try rotating the glass counter-clockwise to remove it an expose the attachment screws beneath.

And yes, turn off the circuit breaker.

Removing the fixture from the wall will expose the wires which are usually attached to the house wiring with wire nuts. Just unscrew the wire nuts to free the fixture from the wires.
Jim

I'd suggest you do everything you can to not have to remove the fixture. I've broken more than I care to think of (both in my personal and professional life), just because they were fragile. You didn't say if your wiring was new or old, but touching cranky old wiring is a recipe for disaster.

Masking tape and/or a steady hand on the paintbrush will make everything easy.

I have two chandeliers in my house and want to take them down to paint them. How do I go about removing them and then putting them back up?