Make sure you unplug your computer from the mains before you open it up.
Be very careful when handling the sticks of ram as they are prone to damage from static. I suggest you either wear an antistatic wrist strap or keep yourself grounded at all times by touching the chassis.
It will still read the same amount of ram, it`s just that in dual channel mode, you`ll get better performance from your ram and therefore your system. See HERE for info on dual channel ram.
Just to ease all doubts off of ur mind, download CPU-Z from here and run it. Click the Memory tab and the Channels # option will be the one ur looking for.