Hereyago - a simple 55 step process to remove the battery. Maybe not impossible but far from simple and not without risk:
https://www.ifixit.com/Guide/iPad+Mi...lacement/36023
Apple offers a battery replacement service - NZ$184 (+ NZ$25 shipping if required)
https://support.apple.com/en-nz/ipad/repair/service/pricing
I suspect that by the time you cost buying the tools, a new battery, other parts and figure in the risk of damage that giving it to Apple is the better option.