Uninstalling didn't seem to work for me after reboot. If that doesn't work for you, try disabling it:

1. Install your new launcher through play store. (I used the Basic Launcher as well).

2. Settings -> Device Preferences -> About. Scroll to "Build" and click on it until it pops up that you are a developer (it will give you a countdown)

3. Settings -> Device Preferences -> Developer options (this was just unlocked in step 2) -> Network debugging (this will let you use adb)

4. Install adb (platform tools) on your computer.

5. adb connect <ip address of your shield>

6. adb shell pm disable-user --user 0 com.google.android.tvlauncher

7. adb shell reboot

Should find yourself in the launcher you installed Note, I also stopped the google launcher (cleared data/reset defaults)/tested the new launcher in the middle. So if these steps don't seem to work, before doing step 5 try doing those and then retry.