2. open your partner's asshole - or better yet, have them open it for you - as wide as possible. this is best accomplished if your partner's asshole has been previously penetrated by some fleshy or non-organic cylindrical solid substance at a prior, yet closely proximital, time.
3. straddle your partner's gaping asshole and poop directly into their butt. once again, this is best accomplished if your feces has some sort of substance to it, e.g. "log" form.
4. enjoy your docking moment like a big poopy Skylab.
(this may take some practice, as the sphincter muscle may tend to constrict naturally in these cases, especially from the docker. if the dockee has previously stretched their butthole, this isn't quite as much of a problem as one would believe.)
Al: Docking's the best, no need to ask!