Does this mean that, in order to make a generic "you" construction in Russian, you just leave the verb as an infinitive?
Like, English sometimes uses "one" as a pronoun, though it sounds a bit old-fashioned ("One can find plenty of fine-dining restuarants on Main Street"); I've seen it in German as "man" ("Man soll niemals 'nie' sagen":"[One should] never say 'never'"), in Dutch as "men" ("Wat men moet leren doen, leert men door te doen":"What one must learn to do, one learns by doing"), and I think it's "on" in French, though I didn't get that far in the course.
At Forvo Pronunciation, audio clips of apparent native speakers indicates that the T at the end of сказать is actually pronounced, unlike the audio here. Reporting this as an error in the audio.
Literal English translation comes out to "how this to say?"
Keep in mind that: 1) Russian doesn't have the same prepositions that English does 2) What you say in Russian is often dependent on and able to be understood based on the context. Asking someone this, they would understand that you were the one asking so you don't need to clarify that in how you say it. Hope that makes sense.