What do you mean by recall? Do you mean bring it back from a village it is supporting?
If so, you need to go to your Rally Point, then click the Troops link on the left side of the screen.
Once you get there, search through your troops, until you find the village that has your paladin in it, and click the "some" or "all" button. "Some" allows you to recall some of the troops in that village. The numbers you enter are the numbers that get recalled. "All" recalls all troops from that village.
