on the contrary... i asked OSS directly and they confirmed they cut it open. I have a bunch of recordings on my process, if you give me a day, i will put together a video of what i did... i have some good tips on how to make a clean cut using a wheels. I plan on doing one too with using a router bit [2 flute solid carbide 1/32" bit
Even though i had some hiccups along the way, it definitely was not because of the cutting process, but because i had shitty headlights to start off with. I've since then had plenty of practice on other peoples' headlights and i think i have it down pat now... ^__^
EDIT: And to add on to LUX's comment, i've tried the heatgun method, it doesn't work... the headlight lens will melt and bubble up before the glue gets soft/sticky in order to peel apart. I also tried heating up just the black housing part (directly behind the clear lens) and again, the housing gets soft and malleable before the glue does. If there's another method out there that someone KNOWS works, then please make a video of your process in order to not only prove me wrong, but to help the rest of use have a clean and professional project we can be ultimately proud of. ^__^
The reason the glue doesn't work like other headlights is because this (like the new GM/Chevy vehicles) headlight uses "Perma-Seal Gasket" it's an epoxy that resists heat below 500°, it's commonly used in making valve cover gaskets. Thus, why a heat gun has no effect.