You don't need to uninstall the browser in order to install its latest version. Usually Internet Explorer updates by itself through Windows Update. Also you can update it manually, if you download and install its latest version over the current one. However, if you want to uninstall it, go to Control Panel > Uninstall a program and select View installed updates below Control Panel Home. After that, scroll down to Microsoft Windows section, right click on the Windows Internet Explorer, press Uninstall and follow the provided steps.