decide on your equipment supplier, imo gardiners and get the lightest and best
set a date
inform all your customers, by letter and verbally
explain it may take a couple of cleans for the system to get into its stride
explain they will get more for their money (frames doors etc)
offer a "rain guarantee", tell them you will be working in the rain, upto a point
explain this as come about because of HSE rules, working at height etc
And this part may be the hardest...............any customer who doesn't want to convert..........................DUMP
this will pay dividends in the long run, even if your business shrinks a little it will give you time to look for new customers to go straight on to WFP