Hi Spencer,
Gene offers some good ideas. If I am seeing the picture correctly. the seal is green. The silver under the seal is the bearing. Both must be installed into the casting. Lacking proper bushing and seal drivers, I have installed a number of seals (and bearings) using the flat end of my sockets. I select a 1/2 or 3/4" drive socket that is nearest under the casting bore size. After the bearing is well seated, use the upside down socket to push the seal, usually without damage. As you probably know, a coat of light lube to prevent galling and keeping it straight the first 1/2 of the way are critical. I know the socket is sort of a down and dirty method, but I am not sure what you are seeking on this one.
Hopefully you will see some better replies.
Charlie V.