Cancelling early. How to and how much?

[#1]

Somebody is moving into my place with me and they want to bring their faster and longer contract broadband and TV with sky to this house, so I want to cancel my own provider and contract as we can't or don't need two different providers for one household.

How do I cancel early? Does it have to be a phonecall? And also how much would it be?
My contact expires in January and their's in July which is also another reason why we want to cancel mine instead of theirs not to mention the faster download speed etc..

Many thanks for any replies.

[#2]

To cancel, you need to phone or send a letter (recorded delivery) to

Plusnet PLC

The Balance

2 Pinfold St.

Sheffield

S1 2GU

To calculate the ETC's multiply your current invoice total - minus any call costs by the number of months remaining. The actual figure may be slightly less, but not by much.