Can anyone help me on this one? I know it has no controversy involved
but hey!!!

IT all depends how mechanicly minded you are, im no expert but i can
say for certain that the big windy belt thing will have to come off and
that alone can take a while to get back on.

When refilling with coolant there is a bleeder valve on the thermostat housing
http://forums.justcommodores.com.au/showthread.php?threadid=12746

You can do it yourself if you have a toolkit that consists of better sockets
that don't have "made in Taiwan" written on them.

I can do them in 30 minutes, the average Joe who possesses some mechanical
aptitude should be able to do them in a couple of hours taking it easy.

1. Remove the fan assembly. Typically four 10mm bolts and an electrical
connector. This bit is optional, but a good idea for a noob since access is
much easier.
2. Crack the four 3/8 or 10mm bolts on the waterpump pulley. Use single hex
sockets to avoid stripping the heads.
3. Remove the belt. Removing the belt is easy, just use socket and
knucklebar or ring spanner to force the belt tensioner against the spring
tension and remove the belt. Draw a diagram of how the belt before you pull
it off to help you when it's time to put it back on.
4. Remove the waterpump pulley. Easy now that you have already cracked the
four bolts in step 2 ;-)
5. Remove the waterpump bolts. You will lose coolant so catch it in
something and dispose of it thoughtfully. You can pull the bottom hose off
and drain the coolant first if you want to, but I normally don't bother.
6. Clean the old gasket off with a scraper and a bit of emery if required.
7. Clean the bolt threads. Don't skip this bit.
8. Apply sealant to the mating surfaces, I use aviation goo but anything
that will tolerate coolant should do. Don't use too much, a thin smear on
both sides of the gasket will be enough.
9. Bolt the waterpump up and torque the bolts to firm, but don't overtighten
in particular the smaller bolts as they snap pretty easily.
10. Refit the pulley. Nip up the bolts.
11. Refit the belt, reverse to removal.
12. Tighten the pulley bolts.
14. Refit the fan assembly if you removed them in step 1. Don't forget the
fan connector!
15. Open the bleeder screw under the engine cover (if applicable, depends on
model). Using an old hose or similar shoved into the radiator filler to
raise the height above the bleeder screw, top up the coolant. When coolant
flows out of the bleeder and doesn't show any bubbles close the bleeder and
bung the radiator cap back on.
16. Start the car, warm it up with the heater on (to bleed any air out)
until the top radiator hose is hot to touch. Check for leaks.
17. When it has cooled down again recheck the coolant level in the radiator.
Don't attempt this with the engine hot unless you're extremely careful, at
normal operating temperature the coolant in the V6 is 104 degrees C!

That's pretty much it I think.

Go to supercheap/repco/autobarn......anywhere shouldnt pay more than $70-80
for it,then pop the bonnet up do it your self...Be usefull for a
change..Takes no more then 1/2 hour.