Water in fuel tank

Well I cannot pull up anything specific on Holden because it is not a US car. There are some US equivalents, but I need to know if it is a VX, VT, or whatever sub-model it is. What I can tell you is that I would take the fuel line off of the fuel filter (possibly under the car, near the fuel tank, on the driver's side), point the line into a bucket, and keep turning the key on for three seconds, and off again, until it runs the tank empty. This will take a while. You might as well replace the fuel filter while you have got it halfway off. Then put some fresh premium gas in it, put it back together, and see how it does.

It probably will not run right, if it starts. In that case, you will need to replace your spark plugs. Then you should, in theory, be good to go.