OK, I assume what happens now is this:
You turn on your router, it starts flashing green on the right, then after some time it starts flashing rapidly.
If this is the case then this means that:
while the light is flashing slowly, it is looking for IP, if it doesnt get response in some time it "gives up" and starts flashing rapidly.
So if this is the case, then plug your meteobridge router via ethernet to your modem. Then, go to a computer that is connected to the same modem and you have to find what IP address was assigned to your meteobridge router. There are freeware programs that will scan your network or it is often listed in the control panel of your modem. Once you find the IP of your meteobridge (usually something like 192.168.xx.xx) you type that into a browser and you should get a dialog for meteobridge login, where you put meteobridge for both user name and password. Then you should be in the control panel of meteobridge, where you set your station, wireless network etc. And once this is set, you can unplug meteobridge from modem and it will connect wirelessly.