Occasionally I, as a layman, say a “Missa sicca” (“dry Mass”), in the traditional Latin EF. One may do so as a private devotion. To the extent my limited knowledge of Latin will allow, I change the prayers — as I am within my rights to do, again, it’s just a private devotion — so that they make sense in the first person, e.g., “peccatis meis”, not “peccatis tuis”, “perducat me ad vitam aeternam”, not “perducat te…”, and so on. I don’t know if the rubrics allow such changes if a priest is saying a “real” Mass sine populo.