Ditto on what timbo said except over here its green.
I would seriously consider draining and filling and bleeding the system or at least get one of the cheap hydrometers that check the coolant quality and freeze point. Over here where we get pretty cold in the winter, its a must.
Unless you have the decks off the easiest way is to pull the radiator hoses off on one end. Remember that in the raised position the radiator is isolated by the trunnion valves and needs to be in the normal position to drain, fill, bleed.
Its great to see you asking all the questions before you bugger it up and there is a wealth of help available here. We all had to and contiune to learn, sometimes the hard way I might add!
Cheers,
Martin.