To remove the oil pan, first jack up the front of the vehicle and secure it carefully on some axle stands. Then, undo the screws and remove the engine undershield, and then drain the engine oil. Undo the bolt or nut and pull the oil level dipstick guide tube from the oil pan. If it is fitted with an oil cooler, this is held to the oil pan by four bolts, undo these bolts and pull the cooler to the rear of the engine, being prepared for the potential spillage of oil. Undo the bolt holding the fuel pipe bracket on the oil pan and remove the wire plug from the oil level sensor. Remove all the bolts attaching the oil pan to the engine, leaving 1 bolt in each corner just slackened a couple turns. Gently tap the sides and ends of the oil pan until the joint breaks and undo the remaining bolts then remove the oil pan and discard the O-rings at the right hand end and prepare to fit new ones. For refitting, make sure you have clean mating faces of oil pan and engine without any residue of the gasket. Apply a thin layer of Volvo liquid sealant to the oil pan mating face by using a short-haired roller. Fitting the O-rings and refitting the oil pan, bolt it in each corner, finger tight only. Insert the oil pan to transmission bolts and tighten them to specified torque and then refit the remaining oil pan to engine bolts, tightening them to specified torque starting at the transmission end. Complete the refitting by making sure you reattach the oil cooler to the oil pan with new oil cooler O-ring seals, oil level dipstick tube is refitted with a new oil level dipstick O-ring seal and oil filter is renewed before filling the engine with new oil.