I would try for a slow weight loss-1-2 lbs a week-to preserve as much muscle as possible.So estimate what you need to lose and just work it out based on,say, 1.5 lbs per week-add a couple of weeks though incase you have underestimated what you need to lose.I dieted for 14 weeks for my first show last year and was in ok condition,maintained the diet for a show 3 weeks later then did the finals 22 weeks after that when I felt I was in 'proper' condition' ie good separation in glutes,lower back,hamstrings,cross striated triceps etc..I then did the UIBBN Worlds 3 weeks later but just felt flat and tired-25 weeks total dieing was a little too much for me maybe?