He doesn't need the money. He's satisfying his sense of order by eliminating debt.
I'd keep the loan. It's at an interest rate that is lower than inflation. Even if you just pay in the ordinary course, you're coming out ahead.
Selling stock makes sense if you knew that a correction is coming. You suspect it, but don't know it. You have to do some speculative math (likelihood of a correction multiplied by multitude of loss) to figure out if it's worth it, but by its nature it's speculative.
Now I will go old school conservative: Remember that your investments are long term investments. Depending on your planned retirement and expected lifespan, you may be looking at a 20-40 year investment horizon even if you're 45. Set it and forget it. Let that money grow over time. Stay the course.