battery removal from a pavillion n3990 labtop

I need instruction for cmos battery removal, foir lost password drainage on th n3990

Are you sure you have provided the correct model number? I can only find about 2 hits on the entire internet about this laptop, and one of them suggests that this laptop was built before 2001. Which would mean this laptop is well past its usable life and not even running Windows XP. We don't support password removal on this forum and I cannot find any information to help you anyways.