I want to disable all services such as: SSH, VNC, etc., so it is impossible to gain access to my Raspberry Pi (It will be running a program using the internet, possibly on public networks.) But, in the future I would like to be able to gain access to it again without a monitor and keyboard, mouse etc. Is this possible?
I am using a Raspberry Pi 3 model B running Raspbian Jessie Lite (2016-11-25)
Also, I would rather not have to buy a console cable. What I have available now is an ethernet cable and the ability to read and write to my SD card.