If they are unreleated to this question than yes. Otherwise ask them here.
On the right side of the symbol editor there are import/export buttons.
Open the first symbol and export it.
Open the new symbol and import the stuff you exported previously.
The post where i learned this sort of thing. (I didn’t know either. I used a text editor to achieve this sort of thing. Very messy.)
If you want to create a multiunit symbol make sure you have the appropriate number of units given in the symbol properties and that you selected all symbols are not interchangeable.
This post of mine describes how to create a multi unit symbol with differing units: (There i gave the example of how to change the logic symbols such that they have the power ports on a separate unit instead of having them hidden on all units.)