Just slide your Mini into the clear-plastic housing (that is, if you can get it open--the locking mechanism requires two hands and some prying with fingernails), close it up, and plug in the special waterproof headphones. The enclosure duplicates the Mini's menu, play/pause, and shuttle buttons--everything but the hold switch. Unfortunately, we found the substitute scrollwheel stiff and hard to turn, and in our tests, it frequently failed to register any movement.
But the real problem lies with the waterproof plastic headphones and their rubberized earbuds. We never could get them to fit comfortably, and only with a lot of wiggling could we actually hear music in both ears. Once we started swimming, the combination of movement and water filling our ear canals changed the tone of the music, dislodged the earbuds, and so on. In short, we quickly came to despise our iPod--not a good sign. Plus, the headphones sounded atrocious: no better than AM radio.
By the way, don't bother bringing the SV iMini into the lap pool without H20 Audio's optional neoprene armband holster ($29.95) or Velcro-based swim belt ($39.95). Carrying the bulky enclosure, which doesn't float, just isn't a realistic option for swimmers.
As much as we understand the desire to keep your tunes playing during aquatic activities, the H2O Audio SV iMini will leave you longing for dry land--and your favorite earbuds.