Stop drinking beer for one. Lift like your life depends on it. You need to go intense if you want to see quick changes. At least 1/2 hour of pure weight training 4 times a week. You will get faster results of course the harder and more often you work out. I do cardio 3 times a week and weights 6 times a week. You do this, along with eating right, you will lose that gut fast, in 3 months, I promise.
Do 30 minutes of medium cardio before lifting weights. Then 30 minutes of weight training, and don't go wimpy here. Be smart but be intense. Push yourself.
Tons of protien 5 times a day, at least 30 grams every meal. Limit most of your carbs until an hour before you work out (I eat 50% of my carbs for the day and hour before my workout). Most of your carbs should be from fruit and veggies, some whole grain pasta is ok and oatmeal is terrific.