Request your assistant hold the picture in place against the wall while you peer behind the picture and simultaneously reach between the picture and the wall and grab the center of the picture's hanging wire.
Lift the picture's rear hanging wire up to remove the slack. The hanging wire is the horizontal wire on which the picture will hang. If you do not remove the slack in it before hanging the picture, your picture will hang up to two to three inches lower than you anticipated.
Drag your hand back and forth along the hanging wire until you reach the approximate center.
Press your index finger tip against the wall at the center of the hanging wire.
Release the wire while keeping your finger in place against the wall. The drill point is where your finger touches the wall.
Mark the drill point with the felt-tip pen.
Drill the drill point with the power drill fitted with the 1/4-inch masonry bit to a depth slightly longer than the picture hanging hook.
Fill the drilled hole with quick-drying mortar using the putty knife.
Insert the1/4-inch angled picture hanging hook into the quick-drying mortar.
Wipe away the quick-drying mortar that spills out of the hole using a damp cloth. Allow the mortar to dry for four to six hours.