On WordPress, WordPress does the updating. FW Real Estate does not download or install anything — there is no update mechanism inside the plugin itself. Each piece is an ordinary WordPress plugin, so backups, rollback and the update log all work exactly as they do for the rest of your site.
The one thing worth understanding before you begin: the pack updates itself; the plugin you update manually. These are two separate operations handled in two different ways.
Back up wp-content/uploads/fwre/ and your database before updating anything. A WordPress plugin update deletes the entire plugin folder and replaces it with the new archive. Your property photos, agent portraits, language packs and any hand-placed add-ons all live under wp-content/uploads/fwre/ — that directory is safe. But if you have placed anything of your own inside wp-content/plugins/fw-real-estate/, it will be gone. The uploads/fwre/ folder and the database together are your real content; back up both.

Update the FW Real Estate plugin first, then the subscription pack. A pack declares the minimum plugin version its add-ons require. If the site is running an older plugin version, the pack withholds its add-ons rather than loading them in a broken state — they simply do not appear. The moment you update the plugin, they reappear exactly as they were. No data is lost at any point; everything those add-ons saved stays in the database throughout.
After any update, the plugin brings the database schema forward automatically on the next admin page load. There is no separate "run database update" step to perform.