Hold the guitar, with the hangers attached, to the ceiling to get a visual of how it will look hanging. Mark the ceiling where the hangers' pre-drilled slots land with a pencil to indicate where you will drill holes.
Attach a 1/2-inch auger bit to the drill. Locate the marks you made and drill through the ceiling material. Stop drilling once the bit punches through the backside of the ceiling.
Insert the toggle bolt into the hollow ceiling by squeezing the toggle clips together and sliding them through the ceiling material until they open on the opposite side. Remove the hangers from the guitar and place them on the ceiling, aligning the pre-drilled slots with the center of the toggle.
Thread the bolts through the hangers and into the toggles. Tighten the bolt fasteners using a Phillips screw driver.
Hang the guitar from the brackets.