If you are that unsure of how to change jets in your bike, or even if they need changing, don't do anything until you get a manual for the bike, and have someone with a little knowledge on the subject help you. If you screw the jetting up very baddly, you can destroy the engine.
Your statement that "it doesn't have the pull that it used to" says that there is something besides jetting at work here. If it ran well before with the current jetting, it still should, so something else has changed. When was the last time the engine had a top-end done? Three years is a long time on a two-stroke top-end, even for a KDX 200:p , and their top-ends last longer than most two-strokes. I'll bet if you check the compression, you will find it is time for a new top-end, and after doing the top-end rebuild, your lost low-end pull will have returned. It is also hopeless to attempt to rejet a bike with a worn top-end. You may also want to thoroughly clean the carb.