hi guys,
i am writting this post,for the sake of tony.
To flush the radiator and engine block, you only have to fill up the system
from the expansion tank and run the engine for some minutes,I say about 10 mins.
(However you can read instructions on the flushing thin which you buy) empty again
refill again and run engine again for so many times until you have a clean drain.
If you are doing this job as a regular service,you only need to watch for any visible
damage to hose pipes,radiator,thermostat housing.
There is no need to remove anything else, unless you are going to restore
the car !! and regarding the drain block plug, be aware because it might be so
much corroded from the inside ( where it is not visible) it might break off while
undoing it and then to replace it may be a hell of a job.