Drilling and tapping blind holes isn't hard. Drilling them in the right places, right depth and tapping them properly is a bit more difficult. (Through-bolting is discouraged. LOL)
The equipment you need is as follows: A centering prick punch, a brass gunsmith's hammer; an electric drill, but preferably a drill press, the correct drill bit, the right number tap and corresponding bottom tap (for blind holes), a T-Handle for tapping, a bottle of Flute-juice or similar cutting fluid.
Tools that help: A vise large enough to hold the parts securely while drilling, a vernier caliper that can measure accurately to .001", thread-locking compound. A Dremel Moto-Tool with cutting and grinding wheels is desirable.
It's critical to determine the thickness of the barrel steel at the point of drilling a hole. This can be done by measuring the outside diameter, delete the bore diameter and divide the remainder by 2 to get the metal thickness. Drilling shouldn't go beyond about 1/3 the metal thickness, preferably 1/4, but at least three turns of a thread...for iron sights. Screws can be ground off or cut with a Dremel, as necessary.
Locate the hole locations by laying the sight where you want it and marking the hole locations with a sharp pencil. Using the prick-punch, strike it with the hammer, dead-center on the hole locations. Check to see if the marks are well-centered by laying the sight back in it it's desired loaction. If a mark is off, it can be moved a bit by holding the punch on an angle and tapping it. Once the marks are in the right locations, deepen them by striking the punch harder.
I've drilled many accurate holes with a regular hand-held electric drill, but it takes practice. Drilling takes careful alignment, but also holding the drill vertical and very steady to keep from enlarging the hole beyond the right size. After starting the hole, check alignment again to see if the drill walked off. If it did, tilt the drill to deepen the hole in the right location, then go vertical again. (If a drill press is used, a centering drill helps to locate holes, but the bits are hard and tend to break off if a hand drill is used.)
Keep measuring the hole depth to assure the proper depth is not exceeded. Remember that extra depth beyond the screw length (as shortened) to allow for the tapping process.
After drilling, start the tapping, using the tap juice and the regular tap in the T-handle. Take a few turns until the tap starts to bind, then back off a turn. Keep doing that until you feel the tap bottom out. (Don't force it or it will snap off and may require a gunsmith to fix it.)
After the regular tap bottoms out, it's time to use the bottom tap. It has a shorter leade, but still needs more depth than the screws. After tapping, clean the holes with a stripped Q-tip in alcohol, then install the sight, checking to assure the holes are deep enough to secure the sight. If not, cut or grind the screws to fit. Use Locktite to secure the screws on the sight.
Hope this helps. It's not rocket science, but it would be a good idea to practice on an old piece of flat metal, then round bar, prior to attempting the rifle. FYI, many sight screws are 6-48 thread and the proper drill is a #31. If you're ordering drills and taps, you may want to order those sizes, just to have them on hand. The other common size is 8-32 and the drill size is #28.
