If the amount is specified on the order the order has the status of a money judgment which means that it can be enforced as a debt.
I'm not completely familiar with the debt recovery process but I know that the person applying to enforce for a small amount pays a small court fee which is added to the debt and warrant enforcement officers then write to you and seek payment. If nothing is paid they attend you home and seek to enforce by taking property. Each time they attend it adds a fee - about £35 - to the debt.
However, warrant enforcement officers are just doing their job and if you call them and offer part payment and a payment plan they could settle for that. There is some flexibility.
Ideally though you should make a payment now to show goodwill and specify when you will pay the rest. Alternatively borrow the money or pay by credit card which is likely to be cheaper that dealing with additional costs of enforcement.