Dropdown menu in the top-right of the UI on a local machine (PC):
Kernel->
Change kernel->
Python 2 (on a local PC)
Python 3 (on a local PC)
My new kernel (on a remote PC)
IPython use kernel is a file in ~/.ipython/kernel/<name>
that describe how to launch a kernel. If you create your own kernel (remote, or whatever) it's up to you to have the program run the remote kernel and bind locally to the port the notebook is expected.