I would be happy to just put a pot on it and be done, but when I researched that solution I read that it is not the preferred method, and to use a transistor.
I got a bit confused at that point. Can someone please point me in the right direction regarding how to proceed? Is the solution as simple as putting a pot inline at pin 15 or pin 16.
It is indeed
as simple as putting a resistor in series with pin 15 or pin 16. You merely have to interrupt that connection between the backpack and the LCD module. The only
reason to use a transistor to control it (as there already is in the backpack) is as noted, to provide software control. In fact, you can
use PWM in software to continuously and rapidly switch the backlight on and off, but this is not always practical.
If you only want to set and not change
the brightness, you just add the resistor. The "setbacklight" function will still turn it on or off.
Alternately, if you want it to be either dim or bright, but never off, you can simply add a resistor between pins 1 and 16 which will set the minimum or "off" brightness.
Just try different resistor values, starting with around 1K.