The word "doer" from James 1:22 in the original language (poiētēs) means to "poetically perform or act out."
The definition of "poetic" is: having an imaginative or sensitively emotional style of expression.
The idea is this; imaginatively and emotionally express the Word of God.
This process starts in your heart.
"Doing the Word" is more than mere outward obedience, it's a process of holding the Word of God in your heart until it bursts out of you as fruit. On the outside, legalism and fruit can look the same. But legalistic acts leave you empty, cold, and faithless.