Write, rewrite, restart, write some more. Keep revising your writing samples until they truly shine. Don't be afraid to write positively about yourself (it is very difficult to do) but don't present yourself as the second-coming. It is best to write about something you personally struggled with and how you overcame it. For me, I wrote about my ACL, MCL and meniscus surgery and how the major change in my physical being completely changed my attitude about how to approach life (I learned who my real friends were, found interest in other activities besides sports, began really pursuing my education). If you write about a personal event that you grew from, you cannot go wrong.
As for the physical side of it, it's all about practice. If you can't do a pull-up, work on negatives everyday. Make sure you do cardio of some kind everyday. Bust out 50 push-ups and sit-ups before bed everyday. You don't have to put in 2 hrs of dedicated time everyday, but add up the little activities and repeat them EVERYDAY.
Also, practice, practice, practice the fitness test. I began practice tests 3 months in advance and ran it every Sunday until my date. You might be able to do max out in all the events separately, together without rest time, it is a whole new ballgame. If you condition your body early to taking the test altogether, it is easier come test day.
Good luck and remember that this is a process. It doesn't come with just one day of work.
C2C of Klepto Class 2016