I want to move to mexico from uk?

This is true, you need to go see or at least write to the Mexican Embassy in London, there they will help you with the paperwork you require, i lived there and did not need a Visa, but i had to apply for an FM2 or FM3, the FM3 is if you want to work so when you get to Mexico apply for one, they will tell you what your require, if you do go, make sure you take translated copies of you documents, Birth Certificate is very useful. Mexico is a cheap country to live but can be hard to find work at time, although the economy is not hit bad with the recession.