Electronic Arts will be sending emails out with redeemable codes inside them, you will then go to this site and redeem the code in order to get access to the Early Access promotion.
Electronic Arts have already started sending out those emails, however most of you will start receiving your emails by midnight tonight(09/26/2011) in order for you to have them in your inbox by tomorrow morning (Tuesday 09/27/2011).
What are the requirements in order to receive Early Access?
In order to qualify for Early Access you must have played Medal of Honor Tier 1 or Limited Edition online and redeemed your Online Pass, or you must have pre-ordered Battlefield 3 via Origin before the 25th of September.
When will I get my email?
Sometime between Midnight tonight(most likely PST timezone) to the early hours of Tuesday morning.
What is in this email?
Information on how to redeem your key, the redemption key, and also a link to the redemption website.
https://bf3beta.battlefield.com/dob/index.php?id=1
Which email is this being sent to?
The email will most likely be sent to your EA Master Account's email, if you have linked your gamer profiles to that email.
Misc..
Emails will be sent to individuals who participated in the Medal of Honor T1/Limited Edition (Xbox 360/PC) promotion with information on how to redeem.
Emails will also be sent to the Origin BF3 Preorder users via their email, with information regarding that.
You will also receive a email if you purchased Medal of Honor via Steam prior to the 25th of July. Your key will be within your Steam Library -- right click Medal of Honor and then click "CD Keys" your code will be listed within that.