To modify the content of already generated steps, first click the relevant step to make it your "current step".
Under such a state, the selected step appears green.
▼(Example) Here, "Enter Text" is the current step
Once this is done, make the necessary modifications under the 4 tags of the Step View: "Basic", "Finders", "Action" and "Error Handling".
For basic knowledge about steps in DS, please refer to the following articles.