You can Jailbreak using Limera1n or Greenpois0n tools, both do the same thing, download it and run it (follow the instructions on the screen and you will be done)
Once Jailbroken, open cydia, search for MyWI, install it and use it.
After the trial expire, you will go back to cydia, put your information (link your ID with either google ID or Facebook), set up your payment (I used Amazon) and you will be done.
Enjoy.