I am trying to make a word game that initially, it has a label and a textinput, after keying input into the textinput and hit enter, i want it to remove the that textinput widget and add 2 things (1) Label with the text (2) A new textinput widget. 
I have been trying to think what should i put for the callback function (fix_it) as the only way i know to remove widgets is by their names i.e. self.layout.remove_widget(self.new_inp), this will remove any subsequent textinput widgets, which i would not be able to see any textinput widgets. 
I would appreciate any help from this community. thank you.
Not exactly sure what you are asking, but the inp argument of your fix_it method is the TextInput instance. So you can remove it with self.layout.remove_widget(inp).
What other ways are there to remove widgets from kivy?