Yes you can if you want to by editing the needed files in ~/.e16/menus/ .... the content is self explanatory if you're used to stuff like that ...... if it isn't: Don't do it!
If you do alter the file, be aware that your edits will be lost every time E16 is regenerated so make a back-up that you can put back.
Other tips (including the menu generation specifics) can be found in this thread:
