You can edit a Joblet just like any other Job in the Integration perspective of Talend Studio.
You can make changes to a Joblet and get your changes reflected in the actual Job execution output. These changes can be made directly in the Job or in a separate tab view.
Note that you can not modify the links of the Joblet directly in the Job.
To edit the Joblet in the Job, proceed as follows:
Click the [+] sign to expand the Joblet.
Double click any component to open its Basic settings view and modify its properties.
Press Ctrl+S to save your changes.
To edit the Joblet in a new tab view, proceed as follows:
Double-click the Joblet you want to edit. You can also right-click it and select Open Joblet Component from the contextual menu.
The Joblet is automatically locked.
Make your changes on your Joblet.
If you modify any trigger link connected to the Trigger Input or to the Trigger Output component, be sure to update the Job using this Joblet accordingly.
Press Ctrl+S to change your changes.
If you do not want the Joblet to open when double-clicking on it, see How to change specific component settings (Talend > Components).