Assuming your diet is in check, cardio is the way to go.
Im fairly heavy so i always use the cross trainer or the stepper and i do it 30-60 mins a day (depending on my goals)
I dont buy into the whole “keep your heart rate at 120BPM” to burn body fat either. Just get in there, get a good sweat going and burn some serious calories!
the better your diet is, the quicker you will see results