No way for the film to adhere again, once it's covered with dirt/debris and lifts off the paint. You'll need to take a razor and carefully score/remove that little strip of film. That's what I had to do with a few areas on my vehicle. Super easy, if you have a steady hand. For those who are not comfortable using/pressing a razor on the PPF and don't want to risk scratching the paint, I suppose you could try cleaning the film as much as possible and then applying an adhesion promoter to help the dirty film stick again.
As for removing dirt that has built up along the normal edges/seams, rubbing alcohol and a Q-tip and/or soft toothbrush has always worked for me.