Patch the game (Your first patch will be over 3 gigs, you need to download the entire game)
The blue "Patch" button will turn into a blue "Play" button whren the patch is complete.
Pressing the "Play" button in the launcher (after you have completed all patches) will send you to the login screen.
After logging in you will be able to select one of the four Trial Mechs and then launch the game with the "Play Now" button at the top right of the client. However, before doing so, I strongly reccomend you use the Tutorial button on the left side of the screen, as well as try out the Training Grounds button a few times.
Edited by Redshift2k5, 04 March 2014 - 09:15 AM.