Click Home (i.e., the name of the currently displayed template) to access the Template Manager (screenshot), then select the template you wish to copy TO (i.e., the template you’re wanting to change).
Once the template you wish to change is displaying in the Editor, click its name to bring up the Template Manager again.
In the Copy from Template drop down menu, select the template you wish to copy FROM.
Click Copy Template, then click OK in the confirmation pop-up window.