Select Risk Register on the side menu and choose the risk you wish to edit.
Select Review Risk on the top panel of the risk.
You'll be taken to the Details page. Here you can edit any of the details of the risk.
To save your changes move onto the Target area. This can be done quickly using the process wizard option on the left hand side of the page.
Scroll to the bottom of the page and please select Complete Review at the end of the Target page.