There are several hitch manufacturers now offering under bed mounts so that when you remove the hitch the bed is left flat, no rails in the bed. My Reese Elite hitch is like that.
And yes, one person can remove it. On mine I pull to pins to release the top section and lift it off. Then rotate four handles to release the pins thru the bed and lift out the bottom section. The bottom section is fairly heavy but manageable, although I usually get the DW to lend a hand with it.
Plastic pucks insert into the bed holes to close/cover them.