To add a new module to a Magento store, uninstall a module, or change the position of a module, you can follow these steps:
Add a new module:
Download the module files from a reputable source, such as the Magento Marketplace or a trusted developer’s website.
Create a directory in your Magento installation with the name of the module.
Copy the files from the downloaded archive to the directory you just created.
Log in to the Magento admin panel and go to “System” > “Web Setup Wizard” > “Module Manager”.
Click the “Enable” button for the new module, and then click the “Apply Changes” button to install the module.
Uninstall a module:
Log in to the Magento admin panel and go to “System” > “Web Setup Wizard” > “Module Manager”.
Click the “Disable” button for the module you want to uninstall, and then click the “Uninstall” button to remove the module.
Change the position of a module:
Log in to the Magento admin panel and go to “Stores” > “Configuration” > “Advanced” > “Advanced”.
Look for the module you want to change the position of in the list, and use the “Move Up” and “Move Down” arrows to change its position in the list.
Save the configuration.
Note: You need to be careful when adding new modules or uninstalling existing modules, as it can cause issues with your store. Make sure to test the store thoroughly after making any changes, and always keep a backup of your store before making any changes. Also, Keep in mind that changing the position of a module will affect the layout of the store, and you may have to adjust some settings accordingly.