Dave
To configure a 302 through the panel you need a 303 display connected to the 302 I believe.

To the OP if you can get a 303 screen attached to your 302 you've really got something! Great wind info, turnpoint data, task making, performance etc etc I think it may have 10 or more pages of info to look at.
But you still cannot install turnpoint data bases, for that you need the utility or a Oudie.
A Oudie with ConnectMe can load turnpoints into a 302 BTW. You can also download your flight into a Oudie. A Oudie coupled to to a 302 and a 303 is pretty awesome even in todays high tech world, and cheap!
That's how I change turnpoint data bases when I travel. Bu using the Oudie. You just need to make sure the Baud rate on the Oudie is set to 4800 to talk to the 302, aren't computers fun?