Hi Pat, the only way you can do it is to clean off any excess flaky paint, fill any holes and then use an electric sander to smooth off, give two good coats of emulsion and then paint your top coat, the other easier option is to have it skimmed by alocal plasterer, this way you get an absolute perfect finish, saves all the mess and its not as expensive as you think.
popeye1948, June 2009