@PB003
Read the info below -- the BIOS and Power On passwords are not stored using the CMOS battery, so removing or replacing those is a complete waste of time.
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To reset Admin passwords, you have to contact your regional HP Customer Support location directly for assistance.
https://support.hp.com/us-en/contact-hp?openCLC=true
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BIOS and power-on passwords are contained in the firmware that is present inside the BIOS chips -- which are soldered to the motherboard and thus, are not replaceable. So, you can't just buy a replacement chip and swap them. Also, neither your nor HP can reset the BIOS password on the current motherboard. Thus, replacement of the motherboard is required with one that has a BIOS chip that does not have a password in the firmware. This is very expensive to do and can often cost more than simply replacing the PC
If you are not prepared to spend the money to get HP to replace the motherboard, you would have to take the PC to a local repair facility to see if they can do anything for you -- but we can not assist in that in any way.
I am a volunteer and I do not work for, nor represent, HP