If an oil leak through the oil pan gasket cannot be eliminated by tightening its mounting bolts, it means that the gasket is severely deformed and must be replaced.
Carry out the work on a lift or inspection pit.
You will need keys 12,14,17 (socket heads), extension, cardan joints.
Remove the engine splash guard.
Drain the oil.
Unscrew the nuts of the two bolts securing the clutch housing to the amplifier and remove the bolts.
Remove two bolts securing the clutch housing amplifier to the cylinder block on both sides...
Remove the clutch housing booster.
Unscrew the nut of the oil cooler drain hose and disconnect the hose from the oil sump fitting.
Remove the eleven bolts and four nuts securing the oil sump to the cylinder block and remove the engine oil sump
Remove the gasket from the cylinder block studs
Before installing a new gasket, degrease the pressure surface of the oil sump and cylinder block, then install the gasket in place.
Install the oil pan and tighten the bolts and nuts securing it to the cylinder block evenly in a crisscross pattern as shown
Install the removed parts in the reverse order of removal.
Fill the engine with oil.