i hear ya, i did my capris tails way back in the day before the interweb and was scared ****less about breaking them. the butyl thats sealing them will probably be stiff so once you get them started it shouldnt be a problem. use a small screwdriver or if you have one a plastic pry tool (not a bad thing to have, you can get a kit at harbor freight cheep) and start working around the edge of hte lens. be gentle, those things have been in there a while! the metal clips are what hold them in so once you get them apart pry the pins on the clips up a touch to make sure they hold the lenses tight. add some new butyl or a thick bead of black RTV in the channel
And final product. I polished the lenses, painted the center bar and restriped. Some fresh Butyl Tape to seal them back up and good as brand new. Not bad for 23 years old.