Watch the video below to learn how to make those slots or mortises in the underside of counter top in which you install miter bolts to join two pieces of counter together.  While some counter tops come with these slots already pre-installed, there are times when you will need to do this job yourself.  With a template or jig (purchased or you can make one yourself), and a router with the appropriate bit, this is a quick and easy task to accomplish, much simpler than you might imagine!  You can probably make the 3 or 4 mortises that you will need to join the two pieces together in about half an hour.  Give it a try, and you’ll be pleasantly surprised at how easy it is!