1, have new radiator handy
2, buy tectaloy xtra cool gold (green colour and concentrate - mix with rain water or distilled) found at sprints or supercheap - this is what I personally use and works a treat other people use different brands etc.
3, make sure you have a drip tray to catch coolant
4, have car on jack stands for easier access or ramps
5, take off radiator cap
6, get underneath car, undo bottom radiator hose, let drain, also make sure your not in its firing line
7, if theres auto trans lines to radiator, clamp them with brake hose clamps
8, remove hoses, minimal auto trans fluid should leak away
9, undo all other hose lines etc
10, remove top brackets + any electrical (if there is)
11, remove radiator - double check to ensure radiator is exact match.
then do the reverse. hope this helps.
ps should also be guidelines on back of coolant bottle for mixing ratios.
*note* tho that you may need to top up automatic trans oil level if there are automatic trans lines connected to radiator.