Hello,

Try to do the following to update the theme:
1. Go to Dashboard -> WoodMart -> Theme License and deactivate the theme.
2. Go to Dashboard -> Updates and click on Check Again.
3. Activate the theme with your purchase code again.
4. Go to Dashboard -> Updates and click on Check Again.
5. Try to update the theme via Appearance -> Themes or via Dashboard -> Updates.
If you are still unable then provide the admin panel login and FTP details of the website.

Kind Regards