If you decide to start a Debt Management Plan (DMP) there is nothing to stop you setting it up yourself. This is regardless of the amount of debt you owe, how many creditors you have or how much you can afford to pay.
More information about this can be found here: Start a DMP Yourself
If you do not want to implement and manage the Plan yourself you can use a debt management service to help you. This can be ideal if you are concerned about negotiating directly with your creditors yourself and you want the simplicity of paying just one payment a month which will then be shared between your creditors on your behalf.
More information about this can be found here: Apply for a DMP