I have irreversible pulpitis. How can I ease pain?

RCT. Get root canal therapy for that tooth asap! The only thing you can do in the meantime is take some otc pain medication.
Two options only. 1. Root canal treatment save a badly damaged or infected tooth instead of removing it. 2. Tooth extraction is the complete removal of a tooth from the jaw bone. Once you have irreversible pulpitis, there's no reversible cure.