You do not need to uninstall the extensions before updating them. In fact, by uninstalling them, you will lose all configurations (module instances...).

Before updating, make sure you read the change logs and are aware of potential backward compatibility issues.

Cached scripts and styles are removed on update. Updates fix issues, add features and/or improve performance and these wouldn't be reflected unless all cached files are re-generated.

Migrating to v2.8.x from v2.7.x

Make sure you update the overrides you may have created (for directory views, module instances and search layout) to get the latest edition features.

Migrating to v2.7.x from v2.6.x

Make sure you update the overrides you may have created to get the latest features.

Migrating to v2.6.x from v2.5.x

The Bootstrap compatibility improvements require all overrides to be updated. Overrides won't fail if you do not update them but you won't get the benefits of updating to this version.

If you are using modals, the extension won't load the MooTools framework anymore.

Migrating to v2.5.x from v2.4.x

Pro Layouts are now placed in sub-folders to become visible and easily accessible in your template's overrides tab. You will need to move your overrides into identically named folders (your overrides won't be visible until you move them). For more information, check the layouts section in this documentation.

Free Pro image improvements will only be available if you update all your template overrides, if you have any.

Migrating to v2.4.x from v2.3.x

If you want to take advantage of the new features for the category index selection box and title links, make sure you update the category index layout and module/view overrides, if you have any.

Migrating to v2.3.x from v2.2.x

The major internal changes applied in this release all have backward compatibility. Nothing will break BUT if you want to take full advantage of the latest improvements, you will need to update the template overrides.

Note that there is a change in the extension's behavior: weblink items won't show if the first image is missing UNLESS a default logo is setup. If show errors is set to 'yes', it can troubleshoot why a module instance or some of the items are not showing or why items are missing in the directory view.

Migrating to v2.2.x from v2.1.x

Layouts and module/view templates have been modified. Although these changes won't break your pages, you will need to update your overrides, if any to get the latest functionality and fixes.

Stylesheets have been modified to better fit your templates and allow for better responsiveness as well as using new techniques for display (flexbox).

The dash after the hits has been removed from the stylesheets, it is now a parameter called 'separator'.

Migrating to v2.1.x from v2.0.x

The caching of stylesheets and scripts has gone through a total rewrite. It is no longer necessary to change file permission access on websites that have very tight security rules. If you have setup file permission access for the files of this extension, you can now safely remove them from your server configuration.

You may still, however, run into access permissions under the new caching system. In that case, it is just a matter of granting access to (or white-list) the /cache folder created for the extension.