Replace clock battery on Dell Inspiron 8200?

Question

I have an old Dell Inspiron 8200 laptop. Still mostly works, but the clock battery has died so everytime I power it on I need to go into the BIOS and set the proper clock time. From what I've been able to tell, replacing this battery is non-trivial, but I haven't found a clear answer.

How do I replace the clock battery? And how do I buy a replacement?

Answer 1

Here is Dell's manual page on replacing the "reserve battery" on the Inspiron 8200.

Here is a model 2664E CMOS Battery (7.2V, 15MAH, 3 pin) for $35, does this look right? It would be nice if Dell's manual gave a part number or some kind of spec.