*DING* LIGHTBULB IN MY HEAD.
1) The other rec is your immediate lead and is writing something good
2) And your previous boss' rec is the one thats weak.....
3) But it might be wierd to very specificially address the recs on your essays
4) Two very different recs are going to make the adcoms wonder. "This guy said great leadership and this guy says weak?"
You now have an essay that completely addresses the gap between the two recs, and make its about positive improvement and not negative. Here is your outline for that essay
* Worked for Boss X on project Y. [THIS IS THE BAD BOSS WHO YOU ARE GOING TO TOTALLY KICK IN THE NUTS WHEN THIS IS ALL OVER. IF YOU DON'T, LET ME KNOW WHERE YOU LIVE, AND I'LL BE HAPPY TO.]
* I knew that back then my leadership and analytical skills were still in need of improvement, so I took it upon myself to A and B [THIS COULD BE EXTRACURRICULARS, A CLASS, MAYBE SOME MENTORING WITH A FRIEND, ANYTHING]
* In that time, I've moved on from that position and believe I have made very large strides in this regard. I currently work for Boss Z [THE GOOD RECOMMENDER] on project X. I am now functioning in a lead role, something that X years ago, I don't think I could have done effectively. For example, [SOME KIND OF LEADERSHIP STORY HERE OR WHATEVER SEEMS LIKE THE MOST IMPORTANT BASED ON THE REC]
* I continue to work on this issue and have in addition taken on leadership roles in X and Y. Today, I am a very different person from the one I was back then - more confident, more able and more self-aware.
* CLOSE WITH A STATEMENT ABOUT HOW K WILL HELP FURTHER YOU IN THIS REGARD
Thats it. Problemo solved, and you've
1) Addressed whats in the rec
2) Explained away the difference between the two recs so it seems logical that your ratings would have changed.
3) Never actually said you read the recs!
4) Turned something negative into something about personal growth