Yup for that type of sling you will need to drill no less than one hole.. That one in the butt, which shouldn't be hard to do neatly. Be certian to stay more into the stock than 1.5 inches from the butt plate, so there is a far better chance no cracks will form.
If you go with another in the fore arm that same rule applies. The other thing to take into consideration is the thickness of the fore arm and the 'flushness fit so nothing hits the barrel once all is said and done.
In the butt stock it helps to use wide 2" masking tape before you lay out and drill anything. Then with a smaller bit press it hard right where you want to start the hole. An awl here can help or a really big nail held in pliers, if you don't have a center punch.
The same applies to the fore arm, and a bit more... You should not just drive the bit thru to the inside. You should use greater care than that, and measure/gauge just what the distance is, and make a marker marking on the brill bit ot tape the bit at the point to stop drill before the bit passes thru the stock. With a sharp pointed awl then you poke a starter hole cnetered in the first hole, and flip the stock over and run the same bit back into the hole you drill from the out side.
This way leaves less chances to gag the bit and tear wood fibers from the stock.
Once you have the correct parts, the job shouldn't take much over 15 minutes counting putting the tools away.
If you purchase a sling stud correctly and these don't have a tool in the kit to turn them with a "L" shape allen tools works well.
Just make sure once the studs are just snug and flush with the wood that the fore arm one doesn't set up too high.
