cut four-inch holes in Pyrex (glass) beakers

I would like 4" holes to be bored in the bottom of my 2000ml erlenmeyer flask, which is made of Pyrex. This involves using a diamond-tipped hole saw / grommet bit on a drill press or something of the sort. Also involves having a water supply or tub to cool. The scope of this job includes designing whatever jig is needed to hold the flask in place while the bit does its job.