Topic: Broken Power Plug on Infocast

I somehow broke the female receptor for the ac/dc power plug on the back of my Infocast.

I took the cover off and here's the picture of the broken receptor:

#1 is the spot where the pin broke off (I believe this would have gone through the center of the ac/dc adaptor male plug.
#3 I believe is the side contact.

Can I simply strip the power adapter wire and solder the + to one of the contacts and if so which one? #1 or #3? Is #2 relevant or is it just the bracket?

And how do I tell (by the way) which wire on the adaptor is the positive? Would a multimeter tell me and how would I use it to tell?

Any other suggestions on how to fix?

I'd appreciate any help. I love the infocast and was shocked that it broke so easily (I had simply pushed the plug in too hard).

Thank you.