Q: How can I merge two symbol libraries into a single symbol library?

A: Open the Symbol Editor, select the Options button and check Append to symbol library and Replace symbols with same IDs in the dialog box that pops up. If you do not check Replace symbols with same ID, all symbols in the two symbol libraries will be maintained. Otherwise, symbols in the current symbol library will be maintained if there are symbols with the same IDs in two symbol libraries. Click OK to close the dialog box. Then you can click Open symbol library to select another symbol library file (*.sym) for the merge operation.