After allowing the glue-ups to dry overnight, remove the table top and shelves from the clamps.
Using a straight-edge and circular saw, cut each of the glue-ups into two at a 45-degree angle, as shown on pages 3 and 4 of the free woodworking plans you downloaded in the first step. Note that for the bottom (and optional middle) shelf, you'll need to cut a few additional notches.
When you have finished cutting the glue-ups into their appropriate sizes, we'll move onto what is probably the trickiest part of these free coffee table plans: cutting out the table top to accommodate the beveled glass top. However, this can be accomplished easily with a jigsaw and a straight-edge (or freehand if you're really confident in your skills) and cleaned up with a sander.
Lay out the cut lines as shown on page 4 of the free woodworking plans. Drill a small pilot hole to get started and cut out the table top as shown. You'll need to cut two of these table-top sections, as they'll be joined along the 45-degree angle in an upcoming step.