can i put the upper part of the passenger side seat onto the driver side lower?

 

you can... but its not worth it. what i did was switch the skins. at the bottom (of the leather ones at least) ITS HELD TOGETHER BY RING BINDS. TAKE PLIERS AND PULL EM OUT.
(sorry for caps, im too lazy to fix) theres also 2 rods held in by rings too farther up, youll find em. then the head rest has 2 c clips in it that hold it on, pop em out and you have a seat skin. just switch the 2 and bam, mint drivers seat

 

You trying to say move the seat over without the rails? No can do, the driver and passenger side are fitted differently(the rails from a passenger side doesn't straight bolt up to a driver side)