i just did this to both my speedo and tach,
thie way took awhile, but it really had minimal damage on the back of the pressed lip
you need a case opener(cheap part from watch shop) and a really small flathead screwdriver.
first mark the halfway mark around where the bezel meet the instrument body.
using the small screwdriver GENTLY and slowly begin encouring the pressed lip up, do this around HALF of the instrument as you had previously marked.
after you have half of the lip pryed up, use the case opener to wedge an opening betweeh the bezel and the body, then leaving the opener wedged it use the screwdriver and starting from the side closest to the opener gently slide it under and wiggle the screwdriver up, alternate side everytime you get a little section lifted up. after half of the bezel is pried up on one side gently push the bezel toward the other half which did not open up. if you did it right the chrome piece will slide right off and the glass comes out as well so make sure the instrument is facing up when you do this!
to reinstall put on the untouched side of the bezel onto the body of the instrument and it will be as tight as it originally was, so this makes it alot easier to repress the lip back on
