In the eclipse ide right click your main project.
Select "Runnable jar or jar"
Fill out wizard 1st page - on that 1st page is Library handling… just select package required libraries with the jar - which is what you want!
Tada! Dont you love eclipse
Remember to check the licenses of the libraries you are packaging with your main project's jar to make sure they play nice with this from a legal standpoint.
Oh dear, sorry about that stupid question. You are right thanks, sometimes things can be so easy.