How do increase the water pressure from my well?

It's done at the switch. This site has a terrific description of how it's done. Thankfully, it's one of those things in life that is simple to do.

How to adjust water pump pressure, pump cut-on pressure and pump cut-off pressure - private pump and well system do-it-yourself repairs (http://www.inspect-ny.com/water/WaterPumpAdjust.htm)

How do increase the water pressure from my well?

Square D tells us that we

Turn nut #1 (the larger spring) clockwise (to the left) to raise [both] cut-on and cut-off pressures.

In other words, adjusting the pressure on this spring shifts the whole operating range of the switch up or down, but keeps the difference between cut-in and cut-out the same, whatever it happens to be (typically it's about 20 psi from the factory.)
Turn nut #2 (the smaller spring) clockwise to raise the cut-out pressure only.

In other words, adjusting the pressure on this spring shifts just the pump cut-out pressure up (clockwise) or down (counter-clockwise).
Hope this helps. Tom