Power off the Dell laptop entirely and then close the lid. Turn the laptop over so that the battery on the bottom side is visible. Push down on the laptop's battery release latch to unlock the battery from the case. Pull the battery out of the laptop and set it aside. http://www.papatek.com/
Turn the Dell laptop back over and open the LCD screen lid back up. Find the black rubber stoppers that cover the screen screws on the top, bottom, and sides of the LCD screen. Pull them out with your fingers or slide a the edge of a flat head screwdriver underneath them to pop them off of the screen. http://www.papatek.com/
Remove all of the screws that were hidden under the rubber stoppers and set them aside. Locate the plastic locking tab that holds the plastic bezel onto the LCD screen at the top of the laptop. Slide a thin flat object such as a screwdriver head in the seam of the plastic piece to access the locking tab. Wiggle the tab to unlock the plastic piece from the screen.
Pull out the screws underneath the plastic piece that hold the screen to the laptop. Pull the screen carefully away from the laptop until you can see the ribbon cable that runs from the screen to the laptop. Disconnect the cable from the laptop and then gently set the screen down.
Remove the screws located behind where the screen was attached at the upper left side of the laptop. Pull off the remaining plastic piece on the laptop lid to reveal the back light. Take off the tape holding the back light in place. Set the new back light into the case and attach it with the tape.
Re-assemble your Dell laptop's screen and then put the battery back in. Power on the laptop and wait for the operating system logo to appear on the screen to make sure the back light was installed correctly. http://www.papatek.com/