Do you have a lid to fit the first drum, a Weber 22.5" kettle lid perhaps? If so I'd just clean it out real good and proceed from there. Much easier then removing an epoxy liner.
Lang 36 patio
18.5" Weber Smokey Mountain
22.5" Weber OTG with Cajun Bandit Conversion Kit
Char-Griller Akorn with side cart
1999 Weber Master-Touch - bent but not broken
14.5" Weber Smokey Joe Silver