Here's what you need to do:
1. LET GO OF THE BAR! Please, for the love of everything thats holy, JUST. LET. GO.
2. Take ONE of the steering lines by the end of the floater
2. continued... AHAH! Which steering line i hear you ask...? Good question. Take the line which is connected to the wingtip that is CLOSER to the edge of the window.
3. Pull the line in so there is constant tension on one of the steering lines (note: keep the bar fully released as you do this - you should create a right angle at your elbow with whatever arm you are using to pull the steering line).
5. Wait some more...
6. As the kite starts to drift toward the edge of the window then one wingtip (which one is connected to the steering line you are keeping tension on) will start to lift off the water.
7. As the kite reaches the vertical C-shape position (as it looks when we launched it on the beach and your instructor gave you the thumbs up signal to let go of the kite) start to ease off the tension.
8. NOTE: THE MOST COMMON MISTAKE AT THIS POINT IS TO PULL THE LINE TOO MUCH AND THUS THE KITE FALLS BACKWARDS, WITH ITS TRAILING EDGE NOW SITTING IN THE WATER!
9. If this happens then swim backwards using your legs and pull both of the middle lines as hard as you can. This will lift the leading edge out of the water and should flip the kite over - at which time you can start this entire process from the beginning).
10. continuing on from point 7.... With the kite in the vertical C-shape position BE GENTLE. Take your time. Make sure the bar is still released and keep a little tension on the (top) steering line in order to lift the kite up from the edge of the window to 12 o'clock. The slower you relaunch your kite the better, as this will result in less power and you not getting dragged farther away from your board.
Here is a link to a super helpful video on YouTube that may give the more visual ones among you a better idea of what we're talking about...
How to relaunch your kite...