Hi,
open file Newspaper/includes/wp_booster/td_data_source.php
To change the Popular (last 7 days) option edit line ~135 (as Bogdan already said -> http://www.screencast.com/t/Z6pW8j6TPh4)
To change the Random posts from 7 days edit line ~169 (I set it to random posts from a month)

case 'random_7_day':
$wp_query_args['orderby'] = 'rand';
$wp_query_args['date_query'] = array(
'column' => 'post_date_gmt',
'after' => '1 month ago'
);
break;