I read in an earlier post about putting lights in the oven.... If you're going to do that - do it with a heated oven with the oven off.... NEVER underestimate the additional radiant heat when that element kicks on....
I've personally taken apart sealed headlights (to reseal) with a heat gun. Just some quick passes to soften the glue/sealant
That said, the drop in variety is the easiest way to go.... Probably much cheaper too (an economist would probably tell you that you'd spend more time than buying what someone already figured out). Unless, of course, you want the individual diode look - something purely aesthetic.