If the epoxy is fairly new you can soften it with heat. It takes days for most epoxy to reach it's final cure strength. I use a variable temp heat gun, but a hair dryer should work. Too much heat can mess up the rod blank finish, so go easy until you get a feel for it. Vinegar will still work on the heated epoxy if it's just a few days old.

If the epoxy has cured a week or more it might be there for good...

For me a popsicle stick makes a better scraper than my finger nails, just as long as it is softer than the rod finish.

If all else fails you can try polishing out the prints using auto body buffing compounds on a soft cloth. They come in a range of grits, producing anything from a matte finish to a mirror. I have had good results using 'Meguir's Mirror Glaze' fine cut cleaner #2. It produces a slightly matte finish that I prefer. You might need several grades to match a mirror finish.

Most auto parts/auto paint stores will carry
buffing compounds, used to remove defect in paint finishes.

Maybe you could cover it up with a decoritive wrap?