How long to change one ?

Is it a PITA like a Pug 405 ?

Yep, pain in the ass. Took me a few hours to do mine years ago. Full dash-out job, and then a nightmare to access because of piping from the aircon and crossmembers.

You can also apparently remove it via the glovebox, but you need to de-gas the air-con as I recall to extract it.

Have fun