Here's another quickie video tutorial showing how to resize a component. In the illustration I have a stile with mortises top and bottom. Perhaps it's for a door except it is too short. If the Scale tool is used to make the stile longer the mortises will get larger too. That's fine if that's what you want but you probably don't.
So, in this example we use a left to right slection box around one end including the mortise on that end. Then we use the Move tool to move the selected bits the distance we want. I placed a construction line as a guide but that's not required.