Here's my cheap alternative to a Tamiya hobby drill for doing the FO - a tiny 12V DC motor with 600RPM reduction gearbox and a mini chuck on the end, for the sum total of 5 quid. I also bought a PWM speed controller in case it was still fast enough to melt the plastic, but it seems perfectly fine without.
Sample holes in the sprue tab.
The only small problem is the motor shaft is a fraction smaller than the chuck, so it's a bit of a sloppy fit. Need to shim it out with something.
http://imgur.com/tPmL3Ps