The motor does NOT ground; it uses a polarity-reversing circuit, so whichever wire is NOT getting +12V, is going to B-. When the switch is not being pressed, both motor wires go to B-. If you're sure about the motor wires in the 2nd pic, then my assumption is that the other 2 terminals near the motor wire terminals are B+ & B-. Then the 2 across the middle are probably for the backlighting. You can test that with a digital meter or powered test light. The switch's motor terminals will be connected (shorted, 0 resistance, light on) to the B- terminal. The 1 terminal that goes nowhere (infinite resistance, light off) is B+. The backlight circuit should have fairly high resistance (a few hundred Ohms, test light dim) between its 2 terminals, which should not ever connect to any other terminal. If the backlight only works with one polarity, then it's an LED backlight and you should note which is the negative terminal. Scratch the markings into the switch body, but if you remove the switches from the bezel, you may find their internal wiring diagrams printed or molded into their sides already. Look VERY closely at the switch terminals for labels (possibly NO, NC, COM, ILL, and a ground symbol).
All the B- and backlight ground terminals should go to a GOOD ground, or a return wire that goes to the B- post. Both B+ terminals should go to a fused +12V source; always-on if you want the windows to always work, but federal law requires all NEW vehicles to require a key for the windows to work. The motor terminals go to the motor wires. If a motor works backward of what you want, simply reverse its wires to the switch. Both backlight terminals go to the dimmed dash circuit (LB/R) if you want them to dim when you twist the headlight knob, or to the parking light circuit (Br) if you want them full-bright all the time.
If you plan to put the switches in the middle of the truck so the passenger can reach them, you're done. If you plan to put them on the driver's side & add a switch for the passenger side, the circuit becomes slightly more complex, and a switch with only 4 terminals (ignore the backlight terminals) won't work on the passenger side. You'd have to find one with 5 terminals (plus backlighting if you want that).