i have an ibanez rg370dx with edge 3. while adjusting the action all i have to do is loosed/tighten the screws with the allen keys or is their anything else to it?
yes...and retune the strings after you're done
You shouldn't adjust the bridge posts' height with the strings and bridge on. Doing so can grind down the knife edges, which will stop your bridge from staying in tune.
Firstly you should loosen all the strings. Then go on with your adjustment.
which part is the knife edges exactly? is it visible while holding the guitar in playing position?
It's the thin part of the bridge that meets the poles you are adjusting. When those edges loose sharpness the guitar goes out of tune easier.