To get rid of the fat you could diet (I lost 30 lbs and at least 25 of it was fat in 3 months by dieting and lifting weights) or you could swim. The explosive aspect is a little more difficult, you could try some olympic lifting and see how your knees take it.

I have used the following programs with athletes recovering from injury - when the nature of the injury allows the athlete to swim or cycle.

Swimming
Day
1 - 1k @ 70%-80% MHR

2 - One length @ 80%-90% MHR - swim back recovery
Two lengths @ 80%-90% MHR - swim back recovery
Three lengths @ 80%-90% MHR - swim back recovery
Keep increasing the maximum effort swims to exhaustion

3 - 1.5k @ 70%-80% MHR

4 - One length or width under water - swim back recovery
Repeat as many times as possible

5 - 2k @ 70%-80% MHR

6 - REST

7 - 6 * 2 lengths @ 80%-90% MHR - with swim back recovery

Cycling - Mobile or Stationary

Day
1 - 20k - 70%-80% MHR

2 - 5 minute slow pedaling @ 60%-70% MHR
20 * 1 minute @ 80%-90% MHR - 2 minutes slow pedaling recovery
5 minute slow pedaling @ 60%-70% MHR

3 - 25k - 70%-80% MHR

4 - 5 minute slow pedaling @ 60%-70% MHR
10 * 2 minutes @ 80%-90% MHR - 2 minutes slow pedaling recovery
5 minute slow pedaling @ 60%-70% MHR

5 - 30k - 70%-80% MHR

6 - REST

7 - 5 minute slow pedaling @ 60%-70% MHR
5 * 4 minutes @ 80%-90% MHR - 2 minutes slow pedaling recovery
5 minute slow pedaling @ 60%-70% MHR

Brian

Thanks for those Programs Brian.
I started using the cycling one a while back and at first the thought of doing long milege on the stationary bike was insane but after a few weeks of doing it my knee stability had improved enough to allow me to start a strengthening program. I have continued with the cycling and will continue to do so as I haven't found anything else that has worked that well for my knee.
Thanks again