Replacing CREE emitter. HELP?

I have a couple Defiant brand 3 cell LED lights. The surface mount LEDs seem to have been knocked off their bases. Is it practical, and/or cost effective to replace these? Which part gets replaced, the disk with the LED mounted on it? I really am quite new to the inner workings, and nomenclature of non traditional flashlights, and their finer points, so please forgive my ignorance.

How do I know which specific LED to use? Seeing as they look to be soldered in place, do most people (without soldering irons, I assume) just throw the light away if the emitter becomes damaged?

Thank you.

Hi!

Normally a LED should not be easy to separate from the base. A solder joint is quite sturdy, and a large force would be needed I think. Next issue, the base should sit flush on the surface under it, ideally with some thermal paste or glue, but not a gap. Maybe it's just a perspective thing in your image.

For replacing LEDs, here's what I did.

That looks a very straightforward repair. You buy the emitter already mounted to the board. So just unsolder and remove old board and replace and resolder the new one. You should use some Thermal Paste between the board and the metal heatsink that it sits on.
There's lots of emitters out there in varying sizes, tints and outputs. To get a decent beam shape you will need a similar sized emitter (Die) to the original. Smaller will give you a tighter beam and larger will give you more spread.
XP-g and ZXP-l are smaller ones, XM-l and XM-L2 are larger. The boards come in standard sizes and the LED will be soldered (already) onto it.
You should pay some consideration to the voltage that is showing at the LED Board and check that your chosen emitter can handle it. Spec sheets are available from the emitter manufacturers websites.
That's the basics, do a little research - the actual repair is easy enough.
here's a good website to show you what you're looking for...
https://www.3tronics.co.uk/accessories
Mountain Electronics in the States is a very useful and reliable source of parts.
P