EAGLE CAD - How To Copy A Symbol From A Library To Another

First of all open the library that contains the symbol you need (from Control Panel window follow the path File > Open > Library). Click on the Symbol Tool located on the toolbar of the Library window you just opened. This will open the Edit window where you will locate and double-click the desired symbol, which will be opened in the library window.

EAGLE CAD - Double-click The Desired Symbol From The Edit Window

Select all the components of the symbol using the Group Tool.

EAGLE CAD - Select The Entire Symbol Using The Group Tool

Click on the Copy Tool and right-click on the symbol. In the pop-up menu that appears select the Copy Group option.

EAGLE CAD - Copy The Entire Group

Now close this library and open the library in which you need the symbol.
Click the Symbol Tool and insert the name of the symbol inside the Edit field. Click the OK button. On the Warning message click Yes.

EAGLE CAD - Insert The Name Of The Symbol Into The Edit Field

EAGLE CAD - Click the Yes Button On The Warning Mesage

What you still have to do is to simply paste the copied symbol using the Paste Tool. Place the symbol wherever you want on the workspace and save it (CTRL + S).

EAGLE CAD - The Symbol Is Pasted Into The New Library

Your new symbol is ready to use!