Before you start adopting XP, you must have a few things already in place. First, you need a team of developers. You should all get along and you should all have some practical experience. You don’t need a team of experts, though having one or two gurus can help.
You need a good source control system. You must be able to work on the system without getting in the way of each other. There must be one single place that holds the most complete, most recent version of the code. It’s very handy to be able to merge and revert changes if necessary. This will save you time.
You must have a customer, though her role can be informal for now. She must have a problem for you to solve. Your goal must be to solve her problem.
As a team of developers, you must be willing to try XP. It’s okay to be skeptical; you can adopt the first few principles and see if and how they improve your work. Adopting XP by yourself in a big team is likely to cause more friction than positive results. Of course, having one developer who refuses to try XP is also difficult. It’s more productive to find a compromise than to work around him.
The first step to adopting XP is to build a healthy team.