Reputation point values can be changed by editing qa.php, which lists the values as follows:
// Reputation multipliers
define( ‘QA_ANSWER_ACCEPTED’, 15 );
define( ‘QA_ANSWER_ACCEPTING’, 2 );
define( ‘QA_ANSWER_UP_VOTE’, 10 );
define( ‘QA_QUESTION_UP_VOTE’, 5 );
define( ‘QA_DOWN_VOTE’, -2 );
define( ‘QA_DOWN_VOTE_PENALTY’, -1 );