If you do not have ADB installed (Mac or Windows), this is a great guide by AFTVnews on how to do so:

http://www.aftvnews.com/how-to-setup-adb-and-fastboot-on-a-mac-or-windows-computer/#toc2


**Note: File Paths can be inserted into Terminal by dragging and dropping folders/files into the Terminal window**


********Connect To Fire TV over ADB********************************************

adb kill-server
adb start-server
adb connect [FireTV-IPaddress]


********Install APK over ADB***************************************************

adb install [File Path to RetroArch.apk]


********Install ROMS***********************************************************

adb shell "mkdir /sdcard/ROMS-ATARI"
adb shell "mkdir /sdcard/ROMS-GAMEBOY"
adb shell "mkdir /sdcard/ROMS-N64"
adb shell "mkdir /sdcard/ROMS-NES"
adb shell "mkdir /sdcard/ROMS-OTHER"
adb shell "mkdir /sdcard/ROMS-SEGA"
adb shell "mkdir /sdcard/ROMS-SNES"

adb push [File Path to ROMS-ATARI Folder] /sdcard/ROMS-ATARI/
adb push [File Path to ROMS-GAMEBOY Folder] /sdcard/ROMS-GAMEBOY/
adb push [File Path to ROMS-N64 Folder] /sdcard/ROMS-N64/
adb push [File Path to ROMS-NES Folder] /sdcard/ROMS-NES/
adb push [File Path to ROMS-OTHER Folder] /sdcard/ROMS-OTHER/
adb push [File Path to ROMS-SEGA Folder] /sdcard/ROMS-SEGA/
adb push [File Path to ROMS-SNES Folder] /sdcard/ROMS-SNES/


********Disconnect From Fire TV*************************************************

adb disconnect [FireTV-IPaddress]
adb kill-server