Hi Oculus forum,
The install process for installing custom sabers in Beat Saber has changed a few times the past 12 months but it's still super easy to setup.
Here is an updated, 100% working tutorial to get you sorted in 5 minutes or less. Video tutorial link at the end for those who prefer:
2. Double click the ModAssistant.exe you just downloaded to run it
3. In Mod Assistant, click 'I Agree', click on the 'Mods' tab, click 'Install or Update'. When it says 'Finished Loading Mods' close down the window
5. Double click the 'CustomSabers\_3.5.1.zip' file you just downloaded and copy the 'CustomSabers' and 'Plugins' folder to this folder on your PC: Program Files (x86)\Steam\steamapps\common\Beat Saber
7. Copy the custom .saber files you just downloaded in to this folder on your PC: Program Files (x86)\Steam\steamapps\common\Beat Saber\CustomSabers
That's it :]