Call out a plumber, jk , i had the same issue, if you are able to get the top cap off, i would use a cloth or latex/basin glove to hold the base and long nose pliers in the fill ports, carefully turn the pliers for leverage, should work unless you have a dudOK I'm losing my pip here , go the tank .... broke first glass on trying to get the damn thing off ....
Chimney does not for a MOER want to come off the base ..... any advise (besides using a hammer) ....