First, you need to take out the driveplate and thereby observe the oil seal,
Oil Pan, surface of the engine block and housing of the rear Crankshaft Seal since an oil pan gasket leak can give the similar sign as a rear Crankshaft Seal leak. Next, the rear Crankshaft Seal housing bolts should be withdrawn and two bolts need to be inserted into the jackscrew holes at the housing then each of the screw should be tightened until the housing is detached from the block, after which it should be removed. Remove the rear Crankshaft Seal from the housing and make sure that there are no nicks grooves or damaged part on the crank shaft. In installation, it is required to clean and check the oil seal housing next, lubricate outer seal face with engine oil slightly while the inner part of the face contacting the crank shaft should be free from oil in a slight sense in order avoid leakage. Fit the seal into the housing to face the lips of the rubber toward the engine; it should be driven in to the depth of the original seal, using a specific tool if available to ensure that it does not go deeper. Extinguish a 3/16-inch wide line of RTV sealant in a pattern to the mating surface of the housing and the engine block, thereafter installing the housing over the block while preventing the seal lips from folding around the rear of the crankshaft. Last, fasten and torque the bolts to the required amount of turn then reassemble the driveplate and transmission.