Adding a library folder to usr/lib (for ofxMASTensorFlow)

I’m on macOS Sierra 10.12.5, and trying to add a library to the usr/lib folder (I’m working on setting up Memo’s ofxMASTensorFlow project)

However, I’m apparently not able to add the libtensorflow.cc.so library to my usr/lib folder.

It’s definitely a permissions issue - apparently there’s a way to fix that by System Integrity Protection, but that doesn’t seem to work on Sierra (I posted in a Stack Exchange forum here)

On Sierra, it seems that when rebooting in recovery mode, there is no longer any way to access a Terminal window (unless I’m mistaken), so System Integrity Protection can’t be disabled by running csrutil disable.

Does anyone have any suggestions?