So... I want to do something and I have no idea what I am doing. It is possible that either me or my car will not survive this.
Any help is appreciated.

I bought the following trunk light strip: http://a.co/5UfDmrh

I think I more or less know how to pull off the trim and access the harness for the lights. Splicing isn't really a problem either.

But here is the question (and you thought you've heard it all! Bet never anything this dumb!) - do I need to disconnect the car battery for this mod?
From what I researched, all tutorials for backup camera say that you should disconnect the battery. But in theory... if the lights aren't on... then I assume no power is being supplied to them. Therefore it should be safe to splice into without disconnecting the negative terminal from the battery?

Or am I doomed with this project?