How do you change a water pump on a VT Commodore is it a big job. Thank you?

i just did one on a supercharged V6 all done in under 30min but the belt tesioners are set up diffrently to a ecotec motor, only pully i had to remove was the one to the right and you need a special security socket to remove it, so far its about the only easy thing ive had to fix on a supercharged V6