Question Unable to remove CMOS battery from sony vaio motherboard

[xs2ahmed]

Hello,
I have a Sony Vaio laptop VGN-FE series which occasionally started and often the time was incorrect, now the laptop does not start, I have opened the laptop and trying to replace the CMOS battery.
Unfortunately I can not unplug it from it's socket on the mainboard.
I have atttached a picture, is there anything special I have to do to unplug it ? I have tried mild force but in vain, any help from the experts please ?

 

[Darkbreeze]

Look to me, from what I can tell of the connector from those pictures, that there is some green corrosion built up in the plug and in the socket. That corrosion is likely what is keeping them together as there shouldn't be any trick to getting them apart and in fact doesn't even seem as though there is a retention clip of any kind on that connector.