Well, how bad do you want it?
It all depends on where you're starting from and how you plan on getting to the destination, with making the proper adjustments along the way.
I had a good base, an unyielding drive and was 110% dedicated ... my results speak for themselves.
So for ME, it was not hard, and in 12.5 weeks I was able to drop 15% bf during my first cutting phase... and over the next 4 months, dropped even further ... ( OF COURSE those figures are open to scrutiny given the debatable subject regarding methods of body fat testing etc... BUT if you want #'s, there ya go)
I would like to see what you think a 'really good diet' would consist of as well.