Need Help on Range?

How would I increase the range of my router? I bought Peplink Balance 20 2 Pepwave Ap 300 Ones and 4 TP-Link omni directional antennas! Is there a specific setting that I could use to gain some range? Maybe changing the channel to a low frequency like 1,6,11? Also, I downloaded the firmware for 3.3.10 , but its a pack! Do I install it one by one or just click on the first one?