Position the safe on the floor where you want to install it.
Open the safe door and locate the mounting holes at the base. Reach inside and draw an outline in each hole using a pencil to mark the location of the holes on the floor.
Remove the safe again and make sure the hole marks are distinguishable. Darken them if necessary.
Drill holes straight down through the flooring at your drawn hole marks using a power drill and a bit that is smaller than the bolt's diameter.
Insert one end of the bolt through the hole and use an adjustable wrench to screw it down into the floor until the threads are no longer visible on that end. Ensure that the bolts go in straight, or they will not line up with the holes in the safe.
Lift the safe and slowly settle it down over the top of the bolts. Adjust the alignment until all four fit through the holes in the safe and the unit is securely planted on the floor. Fit the washers and nuts over the ends of each bolt and tighten them down using a socket wrench.
Fit the plastic caps over the tops of the bolts and nuts to hide them from view.