To cancel directv there will be a cancellation fee that you will have to pay but even if you pay it you will still save money in the long run without the constant directv bill.
To cancel the directv service you'll have to call them up and go through the hoops to get it cancelled. They have a retention department that will do everything they can to keep you as a customer.
You have to resist and demand politely that they cancel the service.
You'll be required to send them the Directv Remote and the Directv receiver which they should send a box for.
If you don't send the equipment back then you'll be charged for it.
They don't require you to send the dish back though so you can either leave that up or take it down and recycle it.