Ok I will try and explain the IKO method which all IKO schools should teach. The best bet would be to see your IKO instructors and get them to explain / demonstrate.
There is a difference between a 5 line kite and a 4 line C or SLE but the principle is the same, you first you need your leash in the right place:
5th Line Kites Leash off the 5th line
SLE Kites Leash off 1 front line
Traditional 4 Line C kites Leash off any single line, front or rear
The reason for this is on a 5th line kite you want the kite to lie on its back and the 4 line kites you want them to flag out down wind. Also SLE kites tend to spin on a rear line leash system (just watch a Best kite) whereas 4 line C kites dont.
In the old days there used to be stoppers on the leashed flying line. If you have a stopper on the leashed line in a 5th line set-up it should be at least a cord width of the biggest kite flown on that bar up the leashed line away from the bar. On a 4 line system the stopper should be at least a wingspan of the largest kite flown on the bar up the leashed line from the bar.
Right, if anyones still reading
When you get into the mucky stuff let the kite onto the leash (quick release) so the kite is only held by ONE line. The kite should now be on its back or flagged out on the water.
Work your way up the leash until you get to the bar making sure that if the kite does suddenly pull several of your digits dont go with it. (its a real bugger to get blood stains off a kite!)
Once at the bar keep hold of the leash line and wrap it onto the bar making sure the kite is still on the water as described. Lock off the leash with a couple of hitches so the line cant come off the bar.
Now, the fun part. Wind in the 4 or 5 lines at the same rate so the kite remains sitting on the water. Do not be tempted to tighten the loose lines! The only line with any pressure should be the leash line. Wind until you reach the kite then lock of the lines with some half hitches. You can then, on most kites, stuff the wound bar and line set under the canopy material of the kite where the main (center) strut meets the leading edge tube. In most kites there is a section where this material is not sewn to the strut and it works perfectly for holding your bar and line set.
You now have options:
1) Hold 1 wing tip and work your way to the other wing tip, bending the kite into a U shape (you may need to release some air.) Holding both corners, use this sail to get home.
2) Lie on the up turned kite, over the centre strut, and paddle home.
3) Deflate the front tube only and role the kite into a raft, get on and paddle home.
Option 1 is the easiest if it will work. Only use option 3 if you know you will make it home. If in doubt, stay with 2 because it is a lot easier for rescue craft to see a bright kite than a black wetsuit!
As stated right at the start If you have not done a deep water pack down you really should take a lesson and get it done. It is a bitch of a job but could save your life.
At IKO schools this is taught before a water start as one of the basic skills!!