Look up RTCOMM Beta and follwo the direction there. Its pretty much step-by-step.

I had no issues using those directions.

If you are missing dependencies, read what they are and search the repositories for them. Usually they are system files and can be downloaded from Extras.

Remember, RTCOmm Beta is exactly that - Beta. You mileage might vary. You might just be better off installing Pidgin for Maemo as it works a little better (esp with IRC) in my experience.