Remove glass top from a TO can packaged VCSEL
I have not used it, but Thor Labs sells a tool for exactly this purpose.



It supposedly works for cans with diameters between 2 and 24 mm.

Note that for a VCSEL there is no "rear facet", so the feedback to the monitor photodiode may depend on a reflection off the can's window. If you remove the can, it may no longer possible to use the photodiode to maintain constant power operation.