There are a few ways to do this.
$file = array(
'Awesomedude123 = 399,408 = September 16, 2012:',
'Username11 = 1,914,144 = September 16, 2012:',
'EpicSurfer = 1,031,427 = September 16, 2012:',
$a = array();
foreach ($file AS $item)
$a = sscanf(rtrim($item, ':'), '%s = %s = %s');
Replace the $file with that of a call to file().
I like dos' suggestion too. Reading line by line is actually better than pulling a full string or an array.
Look into the use of fscanf instead, which saves the need for a file() and foreach() call.