I am stupid..

I accidentally shot 30 minutes of footage in 4:3 when I meant to shoot it in 16:9 to match the rest of the footage I shot earlier for the same project.

The best way to fix this is to re-shoot.. but in my case, that is going to be almost impossible... So, in Premiere, is there any way I can add my own letterboxing to the 4:3 footage and therefore turn it into 16:9 by blacking out the top and bottom?

thanks