I don't think it's a very good idea. I understand one might prefer physical keys to the TB but no function keys and no TB is probably going to cause quite a few problems.
For one you'll have to go in the settings every time you want to change the brightness, sound, keyboard brightness etc. Also, the escape key can be useful/necessary for some applications.
Then there's the whole voiding your warranty and risking to break an expensive computer issue. I doubt they'll do it at the Apple Store.
If battery is the main concern maybe try to dim your screen a little first?
If you still want to unplug the TB you can take a look at this:
https://www.ifixit.com/Teardown/MacBook+Pro+13-Inch+Touch+Bar+Teardown/73480
Step 15 is what you want to do.