In my case it became clear once I got the 13/60 back in the garage, that the repairs to the chassis where more than first thought. So removal of the Tub`s became inevitable to gain proper access. "How Long" the process takes is dependent upon the amount of time available, if DIY, as in my case, or the depth of pockets, if you hand it to the Trade/Professional. I started in Nov 2015, and it has been a sporadic journey ever since, often not getting any work done for weeks, then periods of intense activity, again 99% DIY based. Mostly around current physical ability and the "caring" duties plus a desire to still travel and use the Camper, which is my wife's "love". It will get finished, when?, I suppose it`s a case of "how long is a piece of string". But as my "old man" would have said, "keeps you out the pubs and off street corners". And I`m not just sat watching the "Magic Lantern" during daylight hours as many of my retired colleagues do/did, beats "waiting for god", that`s for sure.
Pete