One of the switches does not work and needs replacing.

 

They're located in front of the gear stick and there's one on either side of the central-locking switch.

 

Can anyone advise what I have to take apart to get access and replace?

Welcome to the forum.

 

Some Fabia with Heated Seats were part of a Service Campaign for Seat Elements & i believe some had switches replaced.

No idea if just vRS or also Monte Carlos. best check if your car needed it or has had it.

 

http://master.skoda-auto.com/mini-apps/recall-actions

I hasten to add that the switch has a hairline crack in it, enough for it not to engage when used.

How easy is the switch to get out? Our passenger seat is only switching it on to position 1. Position 2 illuminates but does not turn on the heating.