Step 1: Login to your WHM panel
Step 2: Click on Manage Account Suspension under the Account Function in menu of WHM.

Step 3: Select the account by clicking on either the username or the main domain on the account.
If you are suspending an account, you can place a note in the box to help remember why it was suspended.

Step 4: Click on either Suspend or Unsuspend
Thats it!!