1) Put soft clean cloth on table or desk; put phone, turned off, facedown on cloth.
2) pry off back (battery) cover
3) using #000 philipps screwdriver, remove screw at bottom left hand side, near charging port.
4) gently pry up plastic insert which the screw came out of.
5) lift port cover (or what is left of it) straight up.
6) Install new cover if you like, and apply steps 4 thru 1 in reverse.