Couldn't have asked for more thanks drain masters! Whether it’s a.m or p.m. With all of this in mind, a system upgrade could take anything between . to . days to complete, depending on accessibility and the complexity of your installation. While you're at it, go ahead and give all of your walls a good scrubbing wipe off any loose dust with a soft cloth, then gently scrub off any dirt with an all-purpose cleaner that's safe for your walls (test in an inconspicuous area first.