Roots Discourse

Best way to update Roots 6.5.1 to Sage 9.0.9?

I have a client’s website that was built on Roots 6.5.1, before Sage was even a twinkle in Root’s eyes.

Currently, it’s affecting the WordPress UI and plugin functionality.

What would the best way to update this theme to the latest Sage and to maintain customization.

Item to note: The person who created this has long left the company, so we are playing catchup without any documentation from them.

Any help would greatly be appreciated!

Thanks,
Brandon