Idk if my hands are that accurate. I'm a shake person unfortunately :/ but if it works I know a buddy who is surgical with stuff like that! Keep me up to date! I was considering LEDs on these s4 lights! Easy 3 strips offset from each other for each light. Throw some resistors for the blinkers and we good!

 

Having done this on both S4 and 4G Mitsubishi Mirage/Lancer (Evo 1-3 model) taillights before, I can say with certainty that a 1000 watt hair dryer, two butter knives and a flathead screwdriver is the way to go. It puts out enough heat to do the job, but not enough to damage anything. Heat it from the housing side and work a knife in carefully, zero cutting needed.

 

Looking forward to trying this on a set of irreplaceable tail lights...