Pushnut/starlock washer install

Originally Posted by bunk

Does anyone know an easy way of installing a pushnut washer aka star lock washer? Im trying to install it on a pin that holds together a linkage joint. Ive tried vice grips, a socket and socket extension while hammering it onto to the post, forcing it in with the washer on a socket and using channel locks.

I cant get enough force onto the washer and keeping the back of the pin steady enough. Is there a special tool for it or a technique?