When starting the repair, always disconnect the battery connector to avoid a potential short circuit. Unscrew the Y-type screws with a Y-type screwdriver and remove the cover plate. Now carefully disconnect the battery connector by sliding it under with a flat plastic tool. We use a plastic spudger for this. Disconnecting the display connectors To avoid damaging something on the logicboard while disconnecting the connectors, you should always use your tools from the side where there are no components.
A few years ago I bought a kit of weird small screwdriver heads from Amazon. I initially bought it because I needed a special tip for removing my Macbook Pro cover to replace the battery. But I've used it for a ton of other stuff since getting this kit.

If you’re like the many, however, who are not covered under Apple’s protection plan, it is still worthwhile to explore other options for getting your iPhone battery replaced. Is your device freezing up when you try to send text messages?
To prevent any loss of data, you should backup your device. Even if your phone is functioning and healthy, you should still back up data from time to time, as you never know when accidents involving your phone could happen. To backup your iPhone with iCloud, you simply need to be connected to wi-fi. Go into settings, choose your name, and tap “iCloud.” From there, you choose “iCloud Backup” and “Back Up Now.” Now you have a backup for your data!