easy enough to drain it, just isolate the the feed & expansion, unless it is sealed system, locate the drain pint attach a hose, open and away the water goes....thats the easy part....
refilling on certail systems can be very troublesome, air locks etc, and water has to be chemically treated with inhibitor or your system will rust from inside out.
an easier solution would be to 'rent' a pipe freezer from a local hire shop, frees the pipe either side of the leak, make your repair, let the pipe thaw, maybe add a little topup water, and away you go.....happy days!
T, July 2008
