Click on Manage Applications. You will be presented with a list of applications you have installed
Select the application you want to uninstall (the main TouchDown application, please do NOT uninstall your key application), and click the Uninstall button.
To install applications using the Google Play Store
Open the Play Store application in the Applications menu
Search for TouchDown. You will then get a list of apps with their description and rating
Click on the application you want: If you are on a device using Android 2.0 or higher (Nexus, Droid, Galaxy), please download "Touchdown for Smartphones". If you are on any previous version of Android (MyTouch 3G, G1), please download "TouchDown 4 Not-so-smart-phones"
To install, just click on the Install button on the bottom of the screen
In the next screen, it will give you more details about the application including the different functionality it will need to access. Please read this information carefully, then click on OK to finish installing the application.