Unless you know a trick, those seals must have the shaft / coupler separated to replace that seal.
That ping or tink could have come from anything including your pull bar. The real test it to pull it over past 2 revs. Put a pipe on a pull bar....
OR,, the horn is bad and pulling B+ down. Put a light on the leads with horn disconnected and watch if B+ stays up or drops. If it drops, start...
