Website refinement

There is a site made 7 years ago with an almost non-functional admin panel. You need to periodically make content changes to the site: add an article, change the name of the section, etc.

The site is written using the Yii PHP Framework, MySQL database, Apache web server

In total, the task is as follows:

1) Go to the server (the site is running in a virtual machine, there is SSH access), and figure out how to make changes to the site.
2) Periodically make changes for a fee or as an option to rewrite the site on Wordpress or something similar.