Ok
 Pretty much everyone here knows by now i bought a Bear KMag.I also got a new string with it but the reinforcment part of the string where you nock the arrow is coming undone how do i fix it where it wont come unravled? Wax?How do you tie it back?Its not all the way undne but about 30%.
 How do you decide where to put the nock point?
Thanks Matt

if it wasnt so bad i would say
super glue

If the serving is broken or worn through, your only choice is to re-serve the string. I have seen servings unravel because they were put on backwards.  Your fingers slowly loosen the serving as you shoot.  You need to tune your bow to find the optimum nock point. Start maybe 1/2" and tune from there.

If the sevrving is coming undone you need to get it fixed before you shoot it more. You could damage the string itself. It would be best if you could take to a shop and have them put a whole new serving on the string. As for your nock measure where it is now if that is what works and set it back to that point. Here is a link that shows how to tie off the serving pretty well. the knot used to tie the end in shown in the fourth diagram down.

http://www.onlinearchery.org.uk/advice/tune/string_making.html

Here's a vid clip on string serving. It is not real clear about how to start the serving, but you may be able to fix your serving by using the back serve method shown here.
http://www.youtube.com/watch?v=KT5dmmTbeo0

You really should get a string server and learn how to do this. It will save you from having to run to the shop and waiting for your bow every time the serving comes apart. And you can use different size material to get proper nock fit.

As to the nock point. Lay a square from bowstring to shelf and put your nock pt. about 1/2 higher than level to the shelf. As you shoot some arrows, move the nock pt. down until you get good flight. Keep lowering 'til you see some up/down motion in arrow flight, then move nock pt. up a little. Then measure nock pt. with your square for future reference.