How to use Twitter API to follow someone

I checked some other similar questions but some of them are old and i'm too new at api for the rest. So here it comes. I have my account's password, i have my username an开发者_开发知识库d i have a person's username who i want to follow. I want to login and follow that person with these information. So far i found out that process is about something called OAuth and i need to use friendships/create at twitter api. (which is : https://dev.twitter.com/docs/api/1/post/friendships/create )

The problem is hell i have no idea about using OAuth or that twitter api. Looked for some demos over internet but turned out empty, please give me a start point about how to use those.

Thanks in advance. (Btw, i will use PHP for process, if it matters)

here are some good tutorials :

http://www.1stwebdesigner.com/tutorials/twitter-app-oauth-php/

http://net.tutsplus.com/tutorials/php/how-to-authenticate-users-with-twitter-oauth/

technically you would need to register your applications, and then simply use a twitter library to do the authentication etc (or you could write your own) and then use the library's functions to send your request with the auth code you get from twitter