Cancelling a contract??

For anyone who has cancelled a contract with a vendor, did you have to send them a letter and if so what did you write. I am planning on breaking a contract with one of my vendors and on the back of the contract it says:
If customer shall cancel this order at least six months prior to the date on which the studio's services are to begin, with a letter, deposit will be returned in full.

Can someone please tell me exactly what I have to write in this letter because I am not sure what to write. Thanks!

Something like...

This letter is to inform you that, in keeping with the terms of our existing contract, [Insert Vendor] is hereby giving proper notice by [insert Names] of the cancellation of the contract entered on [insert Date], effective immediately.

Don't know the terms of your contract are...if you get your deposit or anything but you should mention that in the letter.

Make sure to date the letter, letter is addressed to the person who signed the contract or if the contract specifies that cancellations should be sent to someone address it to them, send a copy of the contract with highlighted cancellation clause, and if you and hubby both signed the contract to both sign the letter.

If you are mailing it, send by certified mail with proof of receipt so you have documentation that they got it.

FM