macbook pro appstore apple id is not editable
Any application downloaded from the App Store will have the account pre-filled like in your example. It would be best for you to complete each of these steps - most importantly the sixth step of a full erase and reinstall.

Since iWork and iLife are all free, you can re-download them once you wipe and reinstall the computer.


https://support.apple.com/en-us/HT201065