Here's the deal...
The upper bezel has a square hole through the bottom center, the top of the flat handle has a square "peg" shaped into the flat handle that passes through the hole in the upper bezel. After the bezel was placed on the top of the handle the handle was put into a machine that peened over the square corners of the peg so that it no longer can back out of the hole it passes through. The lens was then glued into the top recess in the upper bezel to hide it all.
Fix:
To save the lens and the bezel: The lenses are extremely fragile, and so are the bezels, anything hard like a knife blade (hard steel) prying against the chromed (soft) pot metal upper bezel, will depress or dent the edges of the sharp upper feature around the pot metal upper bezel, this is not repairable once done. The lenes were fragile and tight fitting being glued in place with a pretty tough glue, same deal, any sharp object prying on them and usually a non repairable scratch or chunk missing will result. I generally pass on trying to save the lens and just buy a new one, they aren't expensive, if the bezel chrome is nice just punch a guide hole in the center of the lens then drill a small hole through it so you can pry it out without prying against the upper bezel edges, this saves the bezel from potential prying damage. I have found that most re-chromers can't do a perfect job on pot metal parts (getting them perfect) and they usually cost more than a reproduction, so, I'd just buy both parts new and go from there.
So, if you are determined to save both original parts caution is the name of the game. Take the handle and imerse it in REALLY hot water (not boiling but hot from the tap). this will allow the glue under the lens to soften a bit. Then it's a matter of VERY carefully prying at the edges with a thin fairly sharp tool (razr blade thin) working around the sides and trying to get the glue to give removing then lens. Typically the black rubberized backing of the lens will come off as it's removed so don't get your hopes too high, they are rarely removable without damage but it won't hurt to try.
The upper bezel is another story, the only way to remove it is to get the lens off and get a small grinder (like a "Wizzer with a dime sized cutting disc) and cut away the peened over corners allowing the bezel to be removed. To replace it grind away the chrome where the two surfaces fit together and add some JB Weld or similar adhesive to retain the new one. Use a dab of clear silicone to replace the lens.