Blow dry the viser and stick an exacto knife under it. Gently pry. The bottom plastic is the same process, it is more difficult.
Easyway to push the unibody/screen apart is pushing hard on the fingerprint reader. No bending/scraping. Going between the screen and body with a pick or blade is stupid.
If you DONT put the 5 screws back in, it makes future servicing easy. The device has dovetail joints that will snap into place and still hold everything together. The phone is easy to bend/shatter anyways. This kind of gives you a removable back.