Looking for advice on removing old O2 sensor....any help?

 

do it with the engine cold. thats my advice, its very easy just follow the manifold back to where it connects to the exhaust pipes, it will be the only wire thingy in it, just get a wrench and start unscrewing it. A bit of advice is to hold it with your hand when you adjust the wrench so the chords that become twisted dont screw it back in.