B5.5 estate interior swap

[stuart/b.mouth]

Hello, I have the opportunity to swap out my old cloth interior for a full leather from another B5.5 estate.
what procedure should I follow to make sure I don't get a airbag go off as I swap? and if the new interior has heated seats and I don't have the wiring (not worried about having them) can I just leave them unconnected without any problems? Also.... is the steering wheel easy to change? cheers everyone.