It is a step by step process- Middot 13-3

The order of the 13 Middot Harachamim is the Divine conditioning of human nature.

The first step of character development is a prerequisite for the one that follows. Only once someone can accept flaws of human nature and disappointments as a fact of life can he rid himself of irrational expectations and strengthen his resolve to accept infractions and imperfections (Middah One). Once he completes this conditioning exercise, when an infraction occurs, he is calm and prepared to react with control and forgive (Middah 2) without anger (Middah 3). When handing down a punishment for the infraction, it will be with compassion (Middah 4) and clarity when the offender asks for forgiveness (Middah 5) because there is no buildup of hurt and anger. He can easily consider the misdeed as a thing of the past, protecting the relationship from harm.

Middah Six and Seven:

Erech Apayim– 
S'forno explains this Middah as Hashem being slow to anger both with a Tzadik and a Rasha. Hashem waits patiently for them to do Teshuvah before reacting.

Rav Chesed–
Rashi interprets this Middah as Hashem giving undeserved kindness to the offender who lacks his own merits for kindness and leniency.

Communication- An infraction does not need an immediate response, and the repercussions of the infraction can be undeservingly kind when one chooses to relate to the individual, not the act. The purpose of the Middot exercises is to give us the ability to separate the human from the action and connect with the person, not their deeds.

Self-Improvement-Practicing these exercises will strengthen his relationships. Expectations hurt, and disappointments come from judging how one's behavior affects the ME. Changing our focus to compassion for the other and dissolving the need for perfect behavior in relationships will clear the way for happiness and enjoyment in all life has to offer.

Emunah, Bitachon, and Kavanah-

Recognizing H'shem as the Master of the Universe who can see through every one of His creations will allow us to stop judging and accept that we all have our own struggles. Only He knows what each individual is struggling with, and He controls what happens in the heavens and the earth. So, let us leave the job of correcting the world to Him and instead learn to love, accept, and enjoy each other. Clearing your heart of pain and hurt by accepting others' infractions as their struggle, not directed at you, will open your mind to focusing on your Tefilot and connection to H'shem.

The 13 attributes are beautifully and concisely translated by  NCSY Education here: https://s3.amazonaws.com/ncsy-education/13%20Middos%20Workbook.pdf.