I'm researching for a product (web app) that I intend to improve which has a sizable user base that logs in on a regular basis. The existing product was not thought through design-wise and needs a lift in experience and aesthetics to say the least. What is the best way I can introduce a new design without upsetting existing users who might have gotten used to the current design albeit its poor experience.
I did come across a few approaches from phased changes, user involvement in the redesign to 'just do it' and handle the flak. I'm a little confused.