I’ve studied through the slogans a dozen times in my life;
these are my musings on the slogan currently, not a formal interpretation.
For that reason they are less about straight Buddhist teachings,
and I think able to be shared with most practitioners of other faiths or no faith
(unless yours doesn’t allow you to read any other tradition.) 
If you have time and the inclination, I published the WHOLE  thang here!

#27.  Work with the greatest defilements first.

Mine was anger.  I had a hot temper, manifesting in yelling.
Until I started tonglen / lojong I had no way in to even begin to stop it,
it just happened so fast.  When I got mad, I could not stop and think.
This slogan helped me tremendously, giving me  a way to work with it.
In fact, before that, when I was angry and knew it was not right (a first dawning),
I wanted to stop but didn’t know how!  I know that sounds funny,
but I actually didn’t know how to stop the anger as I began to see it was inside me.
When I knew that I was the one angry, the other person might not be anything but stunned at my response. then the guilt and no way to stop it (in my mind) made the situation worse for me and then I was crying and angry.   A MESS.

I began to stop trying to talk (or holler) when I realized that
my triggered angry response was inappropriate.  I said I needed a break.
I went in and wrote about being angry, then when that was exhausted I began to stop writing about it altogether, the story line as Pema Chodron calls it.
(This was before her writings.)
Instead I did zazen, sit meditation, and felt into the places I was angry.
Of course, this synopsis did not happen fast, but soon I realized that my anger
was all about hurt feelings.   Underneath the anger, especially the hair trigger emotional anger that did not seem justified to others, was hurt, tremendous hurt,
hurt that had built up for a lifetime of not knowing how to deal with it.

I started dealing with it.  “That hurt my feelings.”

Sometimes that got me nowhere in terms of the other person, but I felt the shift in me.
Now I had to learn what to do when they didn’t care if it hurt.
How did I take care of myself?

It didn’t happen overnight but over a 1-2 year period, and then years after as I found ways to deal wit the hurts that never went away, the hurts that were intentional by the “other”, the hurts of the world, the hurts I felt on another person’s behalf, and on and on.

Seems like the reason I was always so angry is that I actually was a sensitive person.
Who woulda thought?

This is by far one of the most difficult and rewarding slogan in my book,
encouraging us to get to it —
or as Trungpa said, “We want to work with the chicken, not the chickenshit.”

*i may have to revisit this one… raw writing, no editing but for spelling*

Okina Journal, with pen and ink,