How to add a RTC battery!

Hi guys,
If you want to add RTC battery, please check the info below!
connector model : Molex 53261-0271.
http://www.molex.com/molex/products/datasheet.jsp?part=active/0532610271_PCB_HEADERS.xml#partdetail
3V Battery like this
https://www.ebay.com/itm/CMOS-RTC-BATTERY-DC09-FOR-ACER-ASPIRE-6920-6920G-8920-RESUME-CLOCK-BIOS-BACKUP/181752874635?epid=1951712147&hash=item2a5150c68b:g:zRgAAOSwnDxUo6pF