Signal issues, where to put antenna?

help please the teardown for this device is very unclear. I was looking at this step. But where exactly are the antenna for each 3G and wifi located .. now once identified can i make antenna better by adding a external wire ... Whenever I go in a building I only have 6 percent signal strength or none walk outside the highest to get his 19 - 27 signal strength percent .. Where exactly would I put that wire and if that is connected to a positive like connect to the negative also I need that for the 3G ... WiFi antenna seems to work decently ...