First things first, losing weight and gaining muscle is never easy. It takes a lot of time and dedication to achieve these goals. Start off by creating yourself a solid dieting plan. Especially if you want to learn how to work lower abs.
This dieting plan should be subject to your own personal goals. If weight loss is your goal be sure to eat in a caloric deficit. If muscle building is your main target you will need to eat in excess. Regardless of the diet, make sure you eat lots of protein. Protein is the muscle building block.
Next, you need to create a workout plan. Be sure not to make the plan to difficult or you will have problems staying motivated. You want to target all muscle group evenly. If your goal is to gain muscle minimize cardio sessions and decrease weight repetition. You want to lift heavy. For fat lose increase cardio sessions and rep count.
Furthermore, obtain a gym partner. Sometimes having a partner will help motivate you to go to the gym and work harder. Especially if this partner is more athletic and fit than you are. Hiring on a personal trainer is also never a bad idea. Especially for those who are unfamiliar with the gym equipment. Most local gyms will offer a personal training service for reasonable prices. I highly recommend Sonus Complete getting a trainer for those who are new to bodybuilding.
Finally, to target the lower abs. Lower abs are usually the last place your body stores fat tissue. It is often the most difficult fat tissue to get rid of. After a moderate cardio warm up you can now target the lower abs. Exercises such as hanging leg raises, reverse crunches, and weighted sit ups all target the lower abs. Perform these exercises at least 2 to 3 times per week. You want to perform roughly 2-4 working sets of approximately 6-10 reps. For fat loss increase the reps to 10-15.
After an intense workout be sure to nourish your body properly. Drink lots of fluids when working out and be sure to consume protein immediately after a workout. I highly recommend purchasing whey protein shakes. These are to be consumed immediately after a workout for best results. Protein shake powders can be found anywhere and are relatively cheap.