If you want to lose lower stomach fat then you will need to lose overall body fat. I think everyone knows this now except for the few that still think they can spot reduce. While it's true that spot reduction is a myth it's also true that as you lose the weight you can target an area so that by the time you lose the fat it will be toned and not flabby.
When you lose lower stomach fat it will be flabby if you don't target it with specific exercises. Who wants to lose weight and be flabby? But I'm getting ahead of myself. First of all the goal is to lose overall fat, since we should all know you cannot spot reduce.
To lose the weight in a timely manner you need to eat 1200-1500 calorie a day, no less than 1200. The first day you learn to count calories and find out how many you're eating daily. Then the second day you reduce by 500 and continue to reduce until you hit the 1500, no less than 1200 goal.
You must keep track of your calories if you're not willing to do this then you're not going to lose weight and keep it off. Right after you begin to cut calories you should start a weight training program. Cardio is good, but weight training is better, since muscle burns calories.
As part of the weight training routine you add ab work, which will target lower stomach fat as well as muscle. Moreover, abs need to be hit hard with a lot of reps and at different angles. Super setting works best as you alternate ab exercises with no rest between sets for 15 minutes.
However, this isn't what makes the weight come off, so don't go there. It's the weight training that takes does it, especially working legs. The legs are the heaviest and toughest muscles to work, so if you work them hard you will burn more calories and lose more fat.
Back to the abs! When the lower stomach needs extra work you spend more time working that area. You do this by doing leg raises, windmills, ab pull ups, vacuum pose and reverse crunches as well as obliques, which are at the sides aka love handles. These all target the lower stomach fat area.
Your ab routine will go as below in super set fashion with no rest between sets. Once you complete the routine repeat it until the 15 minutes is up. If you're a beginner then build reps, sets and intensity over time.
20 oblique twists 50 bicycle abs and 50 leg raises 5 vacuum poses hold for 15 seconds 50 reverse crunches and 50 windmills
If you don't know how to perform the exercises you can view them on youtube and check resources below that show more detail.