You ask for some way of completely eradicating irritability. The inclination to irritability is given us to use against sin, and we were never meant to use it against our fellow men. When we do, we act contrary to our true nature.
We ought not to grieve or become irritated at anything because, by frequent vexation and irritability, we form the morally and physically very injurious habit of irritability, whilst by bearing opposition with equanimity we form the good and useful habit of enduring everything calmly and patiently.
Solitude offers us an excellent opportunity for calming our passions and giving our reason time to remove them thoroughly from our soul. For just as wild animals can be soothed by being stroked, so all our anger, fear and stress, which poison and disrupt our soul, can be soothed by an atmosphere of peace where the freedom from constant disturbance ensures that our soul can be brought more easily under the power of reason.