Advice needed about an Air to Coil Spring Conversion on a TD5

I have the usual problem on my TD5 with the air suspension on the rear deflating.

I'm intending to do coil spring conversion - is it a difficult job to do? i also understand you would then need to get the ECU adjusted to know the air springs are no longer fitted - is this right and is it expensive?

Thanks alot in advance

its easy to do and yes you do need to tell the ecu about the change there may be some one local that can do it if you post where you are but most places charge £30-£50