Lift the home button end of the front panel up to gain access to the connectors near the top of the phone.
Open the display to about a 90º angle, and lean it against something to keep it propped up while you're working on the phone.
In a pinch, you can use an unopened canned beverage to hold the display.
Add a rubber band to keep the display securely in place while you work. This prevents undue strain on the display cables.