how do you change the internal battery that controls settings?

There is no dedicated battery for NVRAM as there is on desktop Macs. Your MBP's NVRAM power is supplied by the built-in one. If it's dead or nearly so it will not retain NVRAM settings, resulting in lots of problems.

What year Mac?

Related article: How do I replace the MacBook PRAM battery? - Apple Community

AFAIK, there is no PRAM battery on the Early 2011 MacBook Pro models. I just double-checked with the iFixIt site's teardown of this Mac laptop and no where did I see this type of battery.