Place a mark on the wall at the height you want the Target wall ledge. Swipe a stud finder over the wall and mark the location of two wall studs.
Hold a 4-foot level across the wall near the stud marks. Move the level as necessary until the bubble is in between the two lines. Draw a faint line on the wall between the two studs, using the top of the level as a guide.
Drill a pilot hole at each stud along the level line with a 1/4-inch drill bit. Measure to the center of the line with a tape measure. Drill a hole the same diameter as the wall anchor with a bit the same diameter as the wall anchor.
Insert the wall anchor sleeve into the center hole and tap it in with a hammer until it is flush against the wall. Install one end of the mounting bracket to the right stud with a wood screw and Phillips screwdriver. Install the opposite end in the same way. Insert a screw through the mounting bracket and into the center anchor. Tighten the screw with the Phillips screwdriver.
Loosen the screws securing the shelf bracket on the back of the Target wall ledge. Drill a 1/4-inch hole in the center of each shim. Place a shim on the back of the wall ledge, lining up the hole in the shim with the screw mounting hole.
Reinstall the shelf bracket onto the wall ledge with the securing screws, with the shims between the wall ledge and the bracket. Hang the wall ledge on the wall with the shelf bracket hooking over the top of the wall mounting bracket.