Cutting portholes in starships was always a tedious business, but after the arrival of the Enterprise D, it became a mind numbing task. The D’s long, skinny windows are a trial, and it’s even more of a chore with the E, because the windows are so small at that scale. Two tools I’ve found that make the chore bearable are the Tamiya Handy Drill and this tool I made from a number 11 blade.
The trick to cutting out the windows is to first dig a trench with the window tool and then drill a series of holes just smaller than the window opening. I then thin the plastic from behind with a round bit in a rotary tool. After that, I use my window tool to punch out the window opening. I won’t say this is an easy process, but the low-speed, battery-powered drill is a godsend.