The core troubleshooting step error 0x302 is to repair the office program. However, if it fails we should uninstall and re-install the program. The required steps help to understand how to install Office and Uninstall/repair Office programs.
Firstly, Press the Windows logo key + X to see a list of commands and options. Next, Click Programs and Features.
After that, Choose the Office program to repair, and then click on the Change button. Now, do one of the following:
Microsoft Office 2019 & 2021 click Repair > Continue. In Office 365 & 2019 click Quick Repair.