We have attached the plugin Mystery Theme Updater which helps you to upgrade premium theme from Dashboard.
- Go to Dashboard >> Welcome >> Recommended Plugins Tab.
- Install/Active Mystery Theme Updater Plugin.
- After that Go to Dashboard >> Themes >> Add New >> Upload Theme.
- Then please select the upgraded version of theme zip file.
At upgrading process you got a link to download a zip file of an older version and also automatically saved in a media library.