Upload the correct extension version and install it via admin panel > Extension > Install Extension > Extension Upload.
For most of the extensions just directly install the extension upgrade without loss of the settings. You do not need to uninstall or delete your existing extension version.
The exceptions to the general rule for specific extensions are listed below:
For upgrading versions of:
1. Telephone Option v1.2.7.4.
2. VAT/Tax Option v1.2.6.4.
3. Advanced Reports v1.2.0.8.
The core/lib/package_manager.php file in some AbanteCart versions must be replaced.Please check the details and find the download here . This should be done PRIOR to install/update of this extension.
For upgrading AbanteCart Core and all versions of Telephone Option Prior to v1.2.7.4, Advanced Reports v1.2.0.8, VAT/Tax ID Option v1.2.6.4:
1. Uninstall the existing extensions.
2. Delete it.
3. Install new version, then setup the settings.