The only thing complicated is getting the Number format right when you import the file into SheetCam. The picture shows all the settings I used.
When importing you use the excellon option.
Then Scam does ALL the work and you will see the toolpathing in Scam and all the tools are set up AND all the operations are done for you. ALL you have left to do is post the program to Gcode. You must select the proper post for your machine . In this case it is the MACH3 post.
(;-) TP