Whenever you use the Google Play (a.k.a. Android Market) website to install an app, you are presented with a list where you can “Choose device on which to install”. If you no longer have a listed device and wish to remove it, or if you wish to rename a device to something different, you can do so by following these steps.
1. Visit the My Devices page. You can get there by scrolling to the bottom of any Google Play page and selecting My Orders & Devices, then selecting the Devices tab.
2. Type in the field under Nickname to rename any device, or uncheck the Shown in menus box to remove the device from the list when installing apps, books or anything else from Google Play. Be sure to click the Update link on the right side when you are finished doing either.