if you mean you have put water instead of oil into engine, then you will need to jack up car, remove sump plug and empty water into a container,remove sump and clean out, take off oil filter and throw away, and leave engine filler cap off and allow engine to drain and to dry out. take off rocker box and spray plenty of WD40 all over tappets, to help dispurse water. replace rocker box top, fitting new gasket, replace cleaned sump with new gasket, refit sump plug, fit new oil filter, fill with correct type & amount of OIL, and hope for the best.
when renewing coolant please use water & antifreeze and Not 10/40 multigrade.
i give up, July 2010