1. Download the most recent WoodMart version from your ThemeForest account.
2. Go to Appearance -> Themes -> Add new
3. Click on the “Upload theme” button and then choose the theme installable zip file in the form.
4. Click on “Install now.“
5. WordPress will show you information about your existing version. Click on the “Replace current with uploaded” button.
6. Go to Appearance -> Install plugins and update WoodMart core plugin.
Let me know the result.
Kind Regards