[s-cars] Heavy door, how do I make it silky smooth again?

[James Murray (QA/EMC)]

My passenger side door has become heavy to close (i.e. needs a good yank
to close), it's not nice and easy like the driver side... I've tried
soaking the hinges with WD40 or the like... but no success. Anyone know
how I can make the door smooth as silk again? 

Tired of passengers having to "slam" the door shut... kinda removes from
being a being a so called "luxury" car...

/Jamu.