To remove the larger passenger door glass, you will need to first, remove the vent window assemblies. There are 4 screws that hold the assembly in place...basically one at each corner of the frame and the 4th at the bottom of the vertical rail. The topmost one is under the window gasket so you'll have to feel around to find it. Once the screws are loose, wind the larger window almost all the way down and then remove the vent assembly. Then guide the door glass back up so that you can reach and remove the clips that attach the lower channel to the arms.
Installation is the reverse of the above.
Liberal use of PB Blaster or WD40 will make the job easier as most of the screws are small and probably rusty.