Firstly, you must login to you account and select "Journey Manager" from the navigation
From the list of journeys you can find the specific journey you wish to "Stop"
Use the search function in the top right of the page if you would like to search using the journey name
Once you have found your journey, you will see the "Stop Journey" button to the right of the screen. Click it.
You will be prompted to confirm your request:
Once confirmed, a status bar will show you the progress of the journey stopping.
(NOTE: on some browsers we are aware of an issue where the status bar will not progress past 50%. If this occurs please don't worry refresh the page and your journey will be stopped.)
You are given confirmation in the "Running Status" field on the journey.
Once in the stopped state, no actions will be taken by the system inline with this journey. All contacts will be held in the stage where they were at time of pausing (once started again, the contacts will continue).