Tapy’ Tap Tap :)
No problem, in general Oxidization on copper/lead/steel battery terminals is surface cosmetic, if left for say 10 years, then it could get a ‘little’ destructive, but really just some helpful taps with a hammer, or focused taps using a flat blade screwdriver/hammer where the seams should move.
Next try giving it a good shoot of penetrating oil and leave it for a night - use a good brand like $6 to $15 bucks.
Lastly get some battery contact spray, a good name isn’t coming to me now, but it will look like a deep red when you spray it on, and i mean alllll over the area, saturate it. Then it should last another 5-6 years before replacing the battery.
PS. Gloves and Safety glasses are a REALLY good idea when doing stuff with corroded battery terminals, that stuff sucks in the eyes!