Reply to Got Focusrite 2i2 + Beyerdynamic DT880, now what?

I made a thread here on the community to find out what I should buy to hear good sound from my poor laptop.
I just bought a Beyerdynamic DT880 and a Focusrite Scarlett 2i2 audio interface.
Now I don't what to install the audio interface before knowing how it works.
Is there something I should know before? Will it replace my laptop's audio? How do I change from hearing using the audion interface + headphones to just the laptop's speakers?

Thanks