ZTHY High Capacity 72Wh 68+ 45N1136 45N1137 Notebook Battery for Lenovo ThinkPad T440 T440s T450 T450s T460 T460p T470p T550 T560 X240 X250 X260 X270 W550 W550s L450 L460 L470 P50s 0C52862 0C52861

Disconnect the AC Adapter from the computer. Power on the system and continuously tap F1 to enter the BIOS. If you receive a general help window, press enter to continue. Use the right arrow key to select the configuration menu. Use the down arrow key to highlight power menu, and press enter. The power sub menu will be displayed. Use the down arrow keys to highlight the disable built in battery option, and press enter. Assure that yes is highlighted and press enter again to power off the system. Allow your system three to five minutes to cool before you open up the cover. Place the unit upside down. Slide the External Battery lock to the unlocked position. Slide and hold the External Battery release latch to the open position. Slide the External Battery out of the chassis. Turn the system over. Insert a straightened paper clip into the release hole of the SIM card tray. Pull the tray fr