Fastest/Most efficient way to lose BF whilst maintaining muscle?

Any tips would be appreciated. I'm 180lbs 12% bf and would like to cut down to 8% ASAP. Whats the maximum cardio I can do without having all my muscles demolished? I'm running 100mg/ day of anavar. I'm looking to cut as much calories as possible so all tips would be appreciated. I'm willing to lose a small amount of muscle mass in return to achieve faster fat loss take that in mind, i just dont want to lose TOO much.

I would recommend changing up your diet, you can try carb cycling. I would also recommend HIIT (sprint regimen)

HIIT. Ridge approves. And after the HIIT, hit it up with a few straight minutes of six inch exercises.