Follow the procedure in Before working inside DELL Latitude E5570 laptop .

Follow the procedure in Before working inside DELL Latitude E5570 laptop .

Remove the base cover.
To remove the DELL Latitude E5570 battery:
Disconnect the battery cable from the connector on the system board.
Remove the screws that secure the battery to the computer.
Lift the battery away from the computer. 
Unroute the cable from the routing channel and remove the cable from the battery.
Source from dell.com

DELL Latitude E5570 7.6V 8260mAh laptop batteries
Voltage: 7.6V
Capacity: 8260mAh (62Wh)
Battery cells: 6-cell
Chemical: Li-ion
Battery Color: BLACK
Condition: new original battery
Warranty: 9 months

DELL Latitude E5570 battery

DELL Latitude E5570 battery

Product link: http://www.storebattery.co.nz/dell-latitude-e5570-7.6v-8260mah-laptop-battery-store-for-new-zealand-p-178089.html