Try and have at least three tanks for this fight with good taunts and at least 4 healers and range dps.
Carefully pull the first two guards into the stairway zone in, they're very social and can add two more guards easily; all four can be killed at the same time with a mid 80's and above raid.
Once inside clear the trash mobs around the room by pulling them one at a time up to the raid near the entry killing the champion last down on the main floor. (Which actually leaves Pawbuster for last.)
Pawbuster uses his weapon to strike the floor during the fight causing aoe stuns. Have MT healers at max range and secondary healers beyond them to cure MT healers so they can in turn cure mt and extra tanks. Have all the tanks fight Pawbuster over the grate and trade aggro as he memwipes during the fight. He also has a knockback. His weapon needs to hit the grate in the floor three or four times during the fight to break the lock. When his health hits 20% and he has struck the floor grate at least three times with his weapon have a range dps throw the switch in the floor next to where he originally stood to open the grate below him causing him to fall through the floor and get killed by the massive fan blades.
During the fight with his memwipe he will want to turn on the highest dps so have all the tanks ring him around the grate and fight for aggro. He must be over the grate when the switch is pulled to drop him through.
Not a hard fight just a little chaotic.