Nothing to lose. It’s not board work so much really, just the two wires that come up from the driver (through the holes in the pill) and connect to the top of the copper mcpcb there by the emitter. Then heat up the copper and see if the emitter will reflow and behave. There’s no need to remove the old solder…a little new flux is all you need. You can if you want but it’s not necessary here. The new flux is a good idea, though (paste or liquid, either way, just make sure it’s a simple electronics flux and not any typical plumbing stuff). Thermal paste…anything will do really, even the cheap free white stuff that comes with various devices (if you have a computer shop or know an IT guy they may have a pile of the little throwaway packets and give you some).
Here’s an old build thread on the S3…should be pretty much the same except for a different driver in yours. Oh…you’ll want some snap ring pliers with fairly small tips to do the retaining ring. If you have some stout pointy tweezers you don’t care about, you can spread and bend those a little and that’s usually ok…or grind cheap needle nose plier tips. Somewhat important to have a decent grip on the little holes in the ring…don’t want to slip out under pressure and damage the driver board or any components that might be on that bottom side of it.