Make life easy, and just pull the hammer and trigger. Some time down the road, hence in the case of a blow primer, your going to have to do it anyway.
http://www.ar15.com/content/guides/assembly/lower/
With the parts out, first run your finger nail down the disco and back of hammer sear edges. If you feel a bur, then stone that bur off while still leaving the edge sharp. Next, dry fit the trigger pin to the trigger and confirm that the trigger rotates cleanly on the trigger. If it does not, then there is a bur on one of the side C channel of the trigger that will need to be stoned off as well.
When you go to put the parts back in, CLP lube the piss out of them, including the pin channel in the parts as well. The pins are not hammer/trigger selective parts so either pin can be use as the hammer or trigger pin , and the disco spring gets installed large coil side down into the trigger slot.
Lastly, as you pull the trigger back, make sure that the tail of the trigger is not binding up on the side slot of the selector U channel, nor the trigger shoe in the bottom of the receiver opening.