Removing battery from toshiba tecra 8100

[ebuck]

removing battery from toshiba tecra 8100 - is there a trick to this - I have been attempting to do this now for about 1 hour and nothing - can not figure out how to take this out

 

[AntiZig]

http://www.davidmo.com/text/tecra_8100_ug_20021219.pdf

pages 102-103