To ensure minimum distortion, wait for engine to cool before removing head bolts (1/4 - 1/2 turn at a time) in the sequence shown in Fig.1. Thoroughly clean head and block faces and check for true. Clean out all thread holes in cylinder block - use an old drill or blast with compressed air (wear goggles for this!). Check the new head gasket - is it the correct one for the engine? Check that the gasket fire ring is not smaller than the cylinder bore; gasket protrusion into the combustion chamber will result in premature failure. Some head gaskets are marked 'TOP' or 'FRONT' to ensure correct orientation when fitted. Most modern composite type gaskets have special coatings and are designed to be fitted 'dry'. A suitable sealant (e.g. Hylomar, Wellseal, etc) may be required for some applications - check fitting instructions or with supplier. And a note of caution! Enlarging gasket water-way holes will not improve cooling efficiency. The size, number and position of these holes has been finely calculated by the engine and gasket designers and any alteration may propagate localised overheating and premature engine failure.