The question is how do you make holes for a string-through bridge?
You need 1/8” holes from the front side which are easy enough to get right using a template. I prefer using the actual bridge as the guide.
But a 1/8” bit will wander as it goes through 1 3/4” of hardwood so you need a way to align the 1/8” hole on the front with a 5/16” hole on the back.
Before CNC, machinists used a simple pin alignment jig for the job. Here’s mine.
a piece of plywood bolted to my drill press table with a 1/8” pin sticking out of it that aligns precisely with the chuck on the press.