I've peeled it off carefully. Once you get started, it gets easier. Goo gone for cleaning. Make sure you get it nice and dry though.
Be sure to add your own scren protector. I've removed the built in otterbox screens for years, but it does sometimes to scratch up the inside on the added screen protector. (I'd hate to see if it actually would scratch a screen.)
I installed an iCarez glass screen protector and it's quite amazing. Fits great with the Defender. (6 Plus)