Lab craft lighting

Or if you are concerned with the possibility of cracking, use the bent-out end of a paper clip with a short 90 degree bend at the end, hook it into the slot at one end of the diffuser and pull it outward and down at the same time. It should not require a lot of force that way.

A forum search should find some long, detailed threads on converting labcrafts to LED. Converting with COB panels is relatively easy, but beware the power consumption, as it's quite easy to exceed the power consumed by the fluorescent originals, and you can end up with something that is way brighter than you need!