You can't. I've tried, it's not possible.
Chewbacker isn't in the Lego Star Wars 3 beta.
You can not unlock Captain Typho on Lego Star Wars 3 Beta.
To unlock Greedo in Lego Star Wars 3 Beta hit enter and type heshotfirst.
padawawnlord
To get Gredo on Lego Star Wars 3 Beta hit enter before you type heshotfirst (you don't half to type it in bold).
You can not get Grand Moff Tarkin in Lego Star Wars 3 Beta. Trust me, I have every character.
lucasarts.com
the station is on the star destroyer
you cant
heshotfirst
you have to poo
nothing