How to I remove existing payment methods which I no longer need or use?

You can make payment methods inactive to remove them from the list by going to the All lists page, hire. 
 

Please note that there is no option to reorder the payment methods. 
 

Here's how to make it inactive:
 

1. Go to the Gear icon, then All lists.
2. Find a payment method you'd like to remove.
3. In the Action column, click the drop-down arrow.
4. Choose Make inactive.
5. Hit Yes.

Let us know in the comments below if you have additional questions.