Solder your BlinkyTape Control Board to the light string.
Us some hotglue to protect the solder joints.
Download PatternPaint from https://blinkinlabs.com/blinkytape/patternpaint/.
Connect the BlinkyTape Control Board to your computer.
Start PatternPaint, if all works start playing.
In my case i had to download the source from their github repo, open the .pro file in QTcreator and run it from there. I run I3 on Arch on a ThinkPad BTW.
Take your ugly jacket, the safety pins and the string. Fix it somehow, Take care not to block it too much.
4Rock the party
In PatternPaint make a cheesy enough pattern to embarass yourself.
Upload to the BlinkyTape.
Show off your lack of taste and efford to your fellow nerds.