To assign a user or role in a step of a process we must follow the following instructions:
Go to the main menu of the platform on the left side and click on settings.
In the workflows and requests section select Workflow 2.0 Templates.
Edit the Workflow template that you need to modify the user responsible for the step.
Delete the user who is responsible for the step with the "X" button next to the name of the person responsible.
Select the new user or Responsible Role from the drop-down list.
Select the "Publish" button located at the top right.