screen protector

I want to install screen protector for my mobile but I am afraid if it goes wrong (like misalignment or air bubbles or if a liquid spills on it) it will become waste (it can happen if I ask anyone else as well). So are there screen protectors/tempered glasses which can be reused?

Got my S7 on launch day (the excitement is still not dying) and the 1st thing that came to my mind is how to protect the shiny back and the curved portions from scratches. There aren't many S7 screen protectors that would protect the curved areas of the glass. Got gadgetshieldz full body...