Export an Endnote Library in RefMan/RIS style format. Under File, choose Export.
Save it in text format with RefMan (RIS) export selected as the output style. You may have to choose "select another style" in the Output Style menu choices and then search for the style. Rename the text file with an .ris extension.
In Elements, expand the plus sign by Publications and click on Import.
Choose Reference Manager/Endnote as the file type and browse to the RIS file location. Click on the Upload button.
Click on the Import button.