The Michtav Meliyahu explains (in the new sefer on Rosh Hashana pg 137):
The avodah of Malchiyos is not enough to subjugate everything we do to Hashem's will by just not doing any sins, but rather we should have no self-will other than doing the Ratzon of Hashem.
How can we get to that level?
This is the Gemora's question, "u'Ba'meh? - and with what?". The Gemara answers, "B'shofar - Tekiya shevarim teruah". The Gemorah on 33b clarifies, "genuchi, viyenuchi, vi'yeluli - sighs, cries and wails" (which are represented by the sounds of the Shofar).
The Shlah (R"H perek Torah Ohr) explains "genuchi" to mean "hasagas choli hanefesh" i.e. recognizing the sickness of the soul. Meaning, to realize that we are really sick and need to completely rely on Hashem - i.e. "to let go and let G-d".
And "Yeluli" means "aveylus al chatoyim gedolim shehem misas hanefesh - mourning over our big sins that kill our souls". As it says, "reshayim bichayehem kruyim maisim - evil ones are considered dead, even in their life time".
When we realize that lusting and acting out is ruining our lives and making life not worth living, it causes us to mourn our own existence.
B"H on GuardYourEyes we have all been working on Malchiyos, and we will all continue to do so together!
Wishing everyone a great and blessed year!