You can alter test questions by going into Content > Tests > List Tests
or you can use this link http://admin.accountname.zuluelearning.com/index.php?section=tests
You will need to go through the folders to find the tests you need to edit, then view the test to view the individual questions.
To check if you have the correct test to edit there is a "view test" icon that allows you to preview the test before you edit it.
Once you click "edit" you should see a tab at the top labelled "Questions"
When you select that tab the questions for the test will display and you can click on the edit pencil to edit the individual question.
A pop up should appear for you with the question details.
In this pop up window you should see the following options:
You can alter these options to update the details of your test.