Find where the libs are installed in your package, typically it is

/usr/local/kicad/share/

Under windows it will be program files/kicad...

In the share directory there are a couple of directories

library = this is where the eeschema parts live

modules = this is where the PCBnew component outlines live

Now a word of warning, if you reinstall kicad, these directories will get

overwritten, so DO NOT store additional libs and modules directly in

them.

Create a couple of sub directories, mylibs and mymodules and put your

extra stuff in there.

Alternatively you can create these in your home directory and work from

there.

What you do next will depend on how you get the new packages. If they are

already in the form of a library then just put the libs and mods into the

correct folder and that's it.

If they are individual parts then you need to create a library and

import the part into it. Don't forget to save the lib.

You do the same thing with the modules.

Once that is done you then have to add the library to the project with

preference > library > add , you then select your new lib and it will then

become available to the project. You do the same thing with the modules

by using the same sequence when using PCBnew.

There is a section in the tutorial that describes the use of the libs and

modules. It is worth working through that a couple of times just to get

the hang of it.