(It is ported from Android Wear).
1. Go to Settings in your Galaxy Gear.
2. Tap Gear Info and check USB Debug.
3. Connect it to your computer, make sure the battery is not low!
4. Download fastboot.zip from attachments and extract it (Make sure you saved it in your Downloads folder) (do not change the name of files)
5. Download Android Wear Launcher from attachments (make sure it is in fastboot folder) (do not change the name of file!)
6. Move apk file to fastboot folder (where you extracted fastboot)
7. Download Samsung USB Drivers for mobile phones (google it)
8. After installing Samsung USB Drivers, unplug gear and plug it again.
9. Open CMD (Command Prompt) as administrator, type
cd Downloads and press enter.
cd fastboot and press enter.
adb devices and press enter.
You will get usb debugging in your gear after typing adb devices in cmd. Press OK in your gear.
after typing adb devices your device will show up in cmd.
type chmod 755 * and press enter.
type adb install "com.google.android.wearablepreview.app-KKWT-1077241.apk" and press enter.
wait and the apk will be install in your gear.
if you did everything right, command prompt will show 'success'.
Open your gear and go to apps, find Android wear and open it. You will now use Android wear launcher in your gear!
You can do the same method to install other apks, i installed nova launcher in my gear too.
Thanks for reading! If it is helped press thanks button