CMOS Battery How did you remove the power button bar inverter. I have removed the keyboard. I don't want to break anything please help?

Http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c01152880/c01152880.pdf
go to Removal and Replacement Procedures, section (5.10 as well as section 5.3)

Download the Compaq manual from their web site. Focus your search on the E500 model.

The document name is c001152880.pdf. Refer to the Removal and Replacement Section.