Hello,I use your wordpress theme but I would like to upgrade to its latest version.
The latest version is available for download from envato.
You can remove the theme in the WP dashboard and install the new version.
Backup your theme options before to be on the safe side.
Alternatively, You backup the old theme folder to have a backup and unpack and copy via ftp the latest version.
the folder location is wp-content/themes/newave-theme
If you did custom work and modified the theme files, you have the merge the changes. A list of updated files can be found here
(scroll to the bottom of the page)