Jailbreaking an iPhone 7 is a process that allows you to bypass Apple's restrictions and install apps and tweaks that are not available on the App Store. Here are the steps to jailbreak your iPhone 7:

1. Download the Pangu jailbreak tool on your Windows PC.
2. Connect your iPhone 7 to your computer.
3. Enable Airplane Mode.
4. Run Pangu as an administrator.
5. Wait for Pangu to detect your iPhone 7.
6. Click on the "Start" button.
7. Wait for Pangu to complete the jailbreak process.
8. When the words "Jailbreak completed" appear on Pangu, your iPhone 7 should reboot and present Cydia on your iPhone's homescreen.
9. Launch Cydia and download tweaks.

Please note that jailbreaking your iPhone can void its warranty and may cause security issues. It is also important to back up your device before attempting to jailbreak it.