Hello
Thank you for your query.
You can download the latest version of SP Page builder pro from here and install it over the previous one.
https://www.joomshaper.com/downloads/extension/sp-page-builder-pro
You do not need to uninstall the previous version before upgrading. The newer version will overwrite the older version.
You can follow the process here in the documentation link below:
https://www.joomshaper.com/documentation/sp-page-builder/sp-page-builder-3/installation#how-to-update
And if you have SP Page builder pro, you will be able to import and use any layout bundles.