how i can make that on libgdx?

Newbie & Debugging Questions
#1

Hello.
I am trying to port my java 2D based game to libgdx and i have some question
i wil be glad if someone can help me

1-
In the java 2D version i have a settings screen that looks like:

https://s29.postimg.org/q89vq43if/Captura_de_pantalla_1055.png

i am not sure how to implement the fullscreen setting and window size setting in the libgdx version
how i can access to the game display to chante that values when the game is running?
i know that i can set fullscreen or window size with config.fullscreen = true; but i am not sure how to do it when the game is running

2-
This is a small question
is really needed to dispose every libgdx objects using .dispose on the dispose method of Game class?
i read some tutorialas and not every people make that with the code example

thanks in advance

#2 
if(Gdx.graphics.isFullscreen())
    Gdx.graphics.setWindowedMode(640, 480);
else
    Gdx.graphics.setFullscreenMode(Gdx.graphics.getDisplayMode());

I don’t think you need to dispose anything if disposing the game means shutting down the java vm for you.

I’m not 100% sure though, it’s good practice to dispose of resources and i would recommend you to handle them precisely.