since you're replacing the clutch you might as well replace the rear main while you're there. but i'd check to make sure that there are no leaks from the pvc valve or valve cover also.
to change the rear main if you don't have the puller, all you need to do is screw a screw intio the rear main ( making sure you dont go to deep and cut grooves into the crank0 and then pull on the screw to remove the rear main.