you will need to locate the coolant reservoir in the engine compartment and it may need some water drained off to get a good quantity of a/freeze in there,especially in this weather,you didn`t say if you were having problems or if your motor is frozen but dont start it to thaw out if it is or you can do some serious damage,if you are struggling to get it topped up/drained get it to a good local garage which shouldn`t charge too much to do this job
cdc, December 2010