'90 240 Horn (with airbag)

The horn on my '90 240 wagon has quit. (It did this once before and
recovered on its own.)
If I ground the black wire at the horn, the horn works.
So, I think the problem is the horn switch.
The problem is that the car has airbags.
My Haynes book shows what to do only for models without airbags.
I have seen some earlier postings on this.
Am I going to have to remove the airbag?
Any way to try to repair the switch without doign that?

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