On my 1961 johnson 40hp engine model # RDSL-23 I have what I guess would be called motor mounts 1 in the front and 1 on either side, the one in front is broke along with the one on the shifter side, I checked both my manuals (clymers and .... ohh I can't remember the name, syloc or something) and neither one has anything about the mounts, How hard are they to replace, and how is it done, any help would be great.