F: Before drilling holes, you'll need to make a grid on the MDF. You can either mark the 25mm squares (1 inch squares) you self with a ruler. But if you get sick of measuring you could use the grid template provided on the bottom of the page. Then draw a bigger grid, in which the templates fit. Simply stick the template to the surface.
G: Drill the holes according to the grid you've just created. Use a dremel and drillbits with a diameter of 1mm (or 1/32 inch) to do the drilling. This job is time consuming, but do not rush. Otherwise you'll break a lot of drill bits.
In total we drilled 96x48=4608 holes, breaking 3 drill bits.
H: Use a sanding machine to remove the burrs on the other side of the sheet. This side will become your playing surface. First sand the surface down with rough paper. Then smoothen it further with fine sand paper. Make sure that the holes are free from waste.