Because you have got to take the pulley wheel off to get the cover off.to gain access
Oops..sorry..I clean forgot that...
Apologies...my fault rushing a response before last minute Crimbo shopping.
To be honest it will be far easier to remove it with the engine in the car.
Ok, so that will then make the actual belt change a bit awkward...
not impossible...but far and away safer than trying to do it out of the car
as you will need to find some way to secure the engine block to then
apply the necessary amount of force to undo the bolt.
Once it is in the car fit the starter motor.
Put the breaker bar + socket on the crankshaft pulley bolt...
Ensure the end of the breaker bar is touching the ground so that
when you 'flick' the starter and spin the crank that the breaker
bar is orientated the right way to undo the bolt.
It may take more than one go to 'shift' the bolt.
This all relies on the breaker bar and socket being of dam good quality
as in the likes of Snap-On, or Mack as the strain/load will be immense.
lesser equipment will break/split/shatter with nasty consequences
if you happen to be in the way !
You could of course give the crankshaft pulley a good few whacks with
a club hammer in an attempt to 'dislodge' the mating face of the bolt
and the pulley etc....or even heat it to take advantage of the primciples
of thermal expansion....
Who knows..it may come off easily, but however or whatever way you
go about it, I think we all wish you good luck.