Focusing on prior work experience that directly relates to the desired position, and not above it, is a must. Also, honestly explain the reasons for the downgrade, offering to commit to a fixed amount of time working for a potential employer and providing a credible story, like the desire to pursue a hobby or passion, as a reason for moving down the career ladder may also be helpful.
Further, one expert said try to avoid being the first to bring up salary in the interview, and if asked, point out the market value for the position is reasonable.