Does anybody know how to dismantle the cateye EL510?

I'm not sure if this is the right section to ask this question, but since everyone here is into lights, so here goes.

I'm currently using the Cateye EL510 together with a Princeton tec EOS helmet light for my night offroading duties. The EL510 is sufficiently bright enough for my leisure night offroading fun, but the lens on it are the transculent with a linear fresnel lens design. My attempts to open up the unit in a non-destructive way have so far failed. I have not figured out a safe way to dismantle the entire unit and replace the front fresnel lens with a clear piece of acyrlic for a better light throw.

Anybody has dismantled a EL510, or EL500 successfully before? Thanks.