Install Open Sans Fonts on ubuntu

[medin2]

Hello Everybody,
I'm new to ubuntu, i loved windows fonts so i downloaded open sans fonts for ubuntu and i installed them, i use Ubuntu tweak to change font, the difficulty is that i don't know which font to choose and map with the default fonts.
The default fonts are :
249966

Open Sans fonts contains :
249967

I don't know which font to choose to replace exacly the default fonts in order to have best font rendering like windows ?

Thanks for help in advance :) .