Step 1:
Log into your account
Step 2:
Select "Web Sites" under Web & Applications
Step 3:
1) Check-mark the Checkbox of the domain you want to "Restart App Pool"
2) Click on "Actions"
3) Select "Restart App Pool"
Step 4:
Click "Apply"
Step 5: [Done]
You will see a Green bar with the information "Action has been successfully performed."