If you have forgotten the password to your Surface Pro tablet and need to reset it, there are a few methods you can try. Here's how to reset a Surface Pro tablet without a password:

1. Using the Password Reset Disk: If you previously created a password reset disk, you can use it to reset your password. Simply insert the disk into your Surface Pro tablet and follow the on-screen instructions to reset your password.
2. Using Microsoft Account: If your Surface Pro tablet is linked to your Microsoft account, you can reset your password online. Go to the Microsoft account password reset page on a different device, enter your Microsoft account email, and follow the on-screen instructions to reset your password.
3. Using Recovery Mode: If the above methods don't work, you can perform a system reset using the recovery mode. Turn off your Surface Pro tablet, press and hold the Volume Up button, and then press the Power button. Select 'Troubleshoot' -> 'Reset this PC' -> 'Remove everything.' Follow the on-screen instructions to reset your device.

It's important to note that resetting your Surface Pro tablet without a password will result in the loss of all your data, so make sure to back up any important files before proceeding.