Hi,
Press the Home Button at the lower-middle part of the device. Tap the Apps icon to show the applications menu. Locate the Internet Application and tap on it. From the internet application window, tap the menu button located on the lower-left. Tap on Settings showing on the menu list. Tap on Content Setting under the Advanced menu. Find the Default Storage and tap on it. It will show an option to tap on "Memory Card" to set it as the default storage for downloads. Let me know if this step worked for you. Thanks!