explicitly stated how to edit PATH

README.md

@@ -61,7 +61,7 @@ If you use `pip`, you can install it with:
 pip install jupyterlab
 ```
 
-If installing using `pip install --user`, you must add the user-level `bin` directory to your `PATH` environment variable in order to launch `jupyter lab`.
+If installing using `pip install --user`, you must add the user-level `bin` directory to your `PATH` environment variable in order to launch `jupyter lab`. If you are using a Unix derivative (FreeBSD, GNU / Linux, OS X), you can achieve this by using `export PATH="$HOME/.local/bin:$PATH"` command.
 
 #### Installing with Previous Versions of Jupyter Notebook
 
@@ -82,6 +82,8 @@ jupyter lab
 
 JupyterLab will open automatically in the browser. See the [documentation](http://jupyterlab.readthedocs.io/en/stable/getting_started/starting.html) for additional details.
 
+If you encounter an error like "Command 'jupyter' not found", please make sure `PATH` environment variable is set correctly. Alternatively, you can start up JupyterLab using `~/.local/bin/jupyter lab` without changing the `PATH` environment variable.
+
 ### Prerequisites and Supported Browsers
 
 Jupyter notebook version 4.3 or later is required. To check the notebook version, run the command: