I have installed Jupyter Notebook on ubuntu 16.04 using pip3. I can execute jupyter notebook command. It opens and shows a list of current path directories.
You don't have to install or uninstall anything. if you are using python 2 use pip to install and upgrade. But if you want to use python3 then follow the steps below:
sudo apt-get install python3-pip python3-dev
pip3 install -U jupyter
jupyter notebook
all the issues or problems of premissions etc will be resolved.