The need to replace rivets with screws may arise from a mechanical failure of the rivets or from a need for access behind some riveted sheet metal. It is your choice whether you utilize a simple sheet-metal screw or a short machine screw with a nut to hold the screw in place. By following a basic process you can replace that rivet with a screw in a few minutes.
Measure the diameter of the rivet with calipers or a tape measure. (The calipers will be much more accurate, as some rivet diameters may be too small to measure with a large-scaled measuring tape.)
Install the correct-sized drill bit into the drill motor and tighten the bit securely. You do not want the drill bit to be any larger than the rivet. Enlarging the hole may weaken the holding capacity of the replacement screw.
Drill out the rivet by placing the tip of the bit into the center hole of the rivet. A properly sized bit will leave only the top "ring" of the rivet around the drill bit. The hole should be completely reamed cleaned of any debris.
Remove the "rivet ring" from the drill bit using the pliers. Twist the metal ring off the bit in a counterclockwise direction.
Place the screw in the drilled-out hole and tighten the screw with the correct screwdriver (either a Phillips head or slotted). If you are using a machine screw with a nut fastener, use the pliers to "back up" the nut by holding it in place while turning the screw with the screwdriver.
Proceed to the next rivet hole that needs a replacement screw. Perform Steps 3 through 5 one hole or rivet at a time, as removing too many rivets without screws to support the sheet metal may weaken and misalign the metal structure.