It may be possible to pry the glass out with a plastic pry tool or guitar pick. Using metal for this risks breaking the front glass.

Another option for removing the front glass is gently pressurizing the light body with compressed air to "pop" the glass out.

A blow off nozzle with a rubber tip can be inserted into the service port hole on the back. It takes very little pressure to force the glass out, only a few psi.

The glass may eject itself from the light during this process, make sure there is a soft place for it to land to avoid breakage.

Be sure to wear safety glasses during this step in case the glass breaks.