I also agree with this. I just kept shaking things until it loosened. Getting it back on was just as a struggle and took some forcing.
If it is being difficult, confirm that you have removed all 6 (SIX) screws. This is from personal experience.
I was unable to remove the top one with the tools provided. I ended up breaking the glass and had to take it piece by piece. It depends the age of the phone and how strong the adhesive was. You can buy replacements on eBay or Amazon ( https://www.amazon.com/Dogxiong-Battery-... ). I bought it while I was fixing the phone since I broke the glass.
I agree with the above comment. My battery came out bent after trying to pry it so much.
I ripped the tape as well, but was able to use it again (hopefully). I don’t know if it completed a circuit or not but we will see how important it is.