I see examples of this case style more often than I care to that has been damaged by the "I wonder if jamming this blade here works?" approach. So don't take case knife to it at any point, please. That bezel is not designed to be pried up from the outside.
It looks to have the "G0" or "Screw-20" case construction (like PollyC describes in the post 7S26B linked to), where you will need a crystal press with a die that fits the small inner ledge of the inner fixing ring for glass, to push the glass/bezel assembly out of the case. Then you will push the fixing ring out from the inside of the bezel, to be able to install the crystal up into the bezel (from the inside), followed by the fixing ring again from the inside, to keep the crystal secured in the bezel. Then this assembly gets pushed into the case, using a plastic bezel gasket on the outside of the bezel/inside of the case frame (depends on the design). I've tried to describe this in the past
, with limited success. I can barely make it through proof-reading this last paragraph as it is, sorry about that. "Snap-4" of the casing guide shows the bezel assembly being taken apart/put back together pretty well:
http://www.thewatchsite.com/d1/files/Casing Guide/03. Casing Guide.pdf
You definitely need good tools and a good understanding of what the components look like. New gaskets and correctly shaped crystals are also a big help (Seiko does not recommend re-using plastic gaskets, and the rubber gaskets are getting pretty tired by now if original). Make sure your replacement has the correct bevel and side-wall height to seal with the crystal gasket correctly.