go to your stock "text messaging app" > Messaging setting
and under test messaging settings, uncheck " Noifications"
sometimes, check in GoSMS setting, it might allow you disable the stock text notification or give instruction on how too.
bingo that is exactly how to do it. GoSMS tells you do not uninstall your stock SMS app but instead just turn off its notifications and you will be good to go. That is all I did. After that you will be promped sometime later on what SMS app you want to use for default but that is pretty easy to change the first time it comes up.