Linea Recta wrote

Any people here have experience replacing
the cmos battery of a laptop themselves?

Yes.

I might have to try that in the near future.
I suppose it is a day's work... or more?

Varys with the laptop. Some of them have full
maintenance manuals available online and it
doesn't take long to do it with the best designed
ones that make it easy to change stuff like that,
its often just taking one of the covers off the
bottom and changing the battery in there.

With others you have to pull the whole laptop
to bits to expose the motherboard etc and that
can take a lot longer.