WARNING: This page is about a different car, the 2003 Mitsubishi Outlander. However, it is still accessible from the selected car via links, so may be relevant.
Apply a small amount of engine oil to the entire inner diameter of the oil seal lip.
Use special tools MB990938 and MD998776 to press-fit the oil seal.
Fig 1: Using Special Tools MB990938 And MD998776 To Press-Fit Oil Seal