Need help - Watchguard Firebox 1000 Site to Site VPN

i'm picking up where an old techinician left off. I personally hate these watchguards. There drag and drop configuration makes things harder in my opinion. Anyway, I need to get a site to site going with these watchguard but I can't delete the old tunnel. Its telling the bad key phrase. I never worked with watchguards before and I'm glad. Can someone please tell me how to totally delete the existing tunnels that were created and how to created a tunnel between two watchguards.

Thanks