Once the beam and leg assemblies have been connected and are stable, we'll turn our attention back to the saw table and attach the compound miter saw to the saw table.
To begin this step, grab the saw table that you set aside earlier and position it onto the beam. The two box structures under the table top should fit snugly (but not too snugly) across the beam, much like a saddle on a horse. The table should be stable on the beam, but might have a very slight wobble (which should not affect the accuracy of the saw).
With the saw table on the stand, place your compound miter saw onto the table. Position the saw so that the fence is parallel to the far side of the beam (as you look at it). Positioning it in this location will allow any stock to be cut to be placed directly over the beam when being cut.
Center the saw on the table using your tape measure and mark the bolt hole locations. (Most compound miter saws have 1/2" diameter bolt holes, so if your unit requires larger or smaller diameter bolts, be sure to adjust accordingly.) Remove the saw and drill the four holes using a 1/2" paddle bit.
Place the saw back on the table and align the bolt holes with the holes in the table. Place a large flat washer between the saw base and the table. Then slip a bolt through each hole in the saw, through the washer and the saw table. On the underside of the table, slip a large flat washer followed by a lock washer and a nut onto each bolt. Tighten the bolts to lock the saw onto the table. Do not over-tighten the bolts, as you don't want to damage the melamine table top.
TIP: Unless you're of above-average size and strength (or are partial to hernias), it is probably a good idea to have someone help you when you remove the saw table from the beam or put it on next time. The saw table with the saw attached can be quite heavy.