How to change current view/layout xml

[wixilol]

Hello!
Im a new developer in android and want some starter help.
I got 2 layout xml files(main.xml and start.xml)

I do not got a button to change and i dont want a button either but how do i change my layout so start.xml become the current view?

So how do i setContentView? i just get an force close error.

Repeat: how do i change the current layout. XD
Please help.

Thanks //Me