It was tough piecing together all the instructions to install stbemu pro on Fire TV 4k. Here’s my current working process:

1. Install stbemu pro apk. Several ways:
   1. Easiest: Download from Aptoide.
      1. NOTE for 4k Firestick (or maybe never devices): You must use 1.1.7 (which is not on the above Aptoide link). Download from modapkdown or dlandroid.com.
   2. Download from random sites using google. Good luck!
   3. Extract it yourself. 
2. Enable Settings > Device > Developer options > Unknown sources > ON.
3. Enable Settings > Device > Developer options > ADB > ON.
4. Find IP of Fire TV. It will look like 192.168.X.X. Two ways:
   1. Check the router for amazon-HASH device’s IP address.
   2. Open Fire TV’s About > Network to look for IP address field.
5. Install ADBlink for PC or MAC.
6. Open ADBlink, put your IP address in the field, and hit Connect.
   1. NOTE: You will need to accept this connection on the Fire TV. You should see a popup there.
7. Once connected, choose “Install APK” from buttons. Select the APK downloaded in step #1.
8. Finally, your app icon may not show on the home screen. Follow this tutorial. Steps outlined below:
   1. Choose Settings > Applications > Manage Installed Applications > App Store > Force stop, Clear data, Clear cache one after another.
   2. Choose Settings > My Account > Sync Amazon Content.
9. You should have an icon under “Your apps and games” section for stbemu.
   1. It may be at the end. Here’s how to bring it front:
      1. Highlight stbemu icon. Choose options button on remote and “Move to front”.
10. Protip: Make stbemu run on Fire 4k boot.