There are some great kits on Amazon that have all the tools you need with a replacement battery. Just make sure you take time with a heat dryer around the edges to open. I did two phones and they can be tough. Also, if it's not the battery Amazon always takes returns. I used this one if it's helpful for you.

https://www.amazon.com/gp/product/B07B8FMFSY/ref=ppx\_yo\_dt\_b\_asin\_title\_o08\_s00?ie=UTF8&psc=1