99 Malibu horn

My 99 Malibu horn is intermittent. The dealer fixed it once, said there was some grit or stuff from the airbag that gets into the horn contacts. So I think I could either vacuum or blow the contacts clean - can someone tell me about a safe way to:
1) disconnect the airbag and
2) remove the cover trim in the center of the steering wheel
3) anything else I should know?
Thanks for any advice.