#register
RewriteRule ^register(/?)+$ index.php?do=register [L]
RewriteRule ^register/validating/(.*)(/?)+$ index.php?do=register&doaction=validating&id=$1 [L]
RewriteRule ^register/validating/(.*)/nextstep(/?)+$ index.php?do=register&doaction=validating&step=2&id=$1 [L]

2. В файле engine/modules/static.php, ищем строки:

} else {
$tpl->set( '{ACCEPT-DECLINE}', <form method= post name= registration id= registration action= . $config['http_home_url'] . index.php?do=register ><input type= submit class= bbcodes value= {$lang['rules_accept']} />   <input type= button class= bbcodes value= {$lang['rules_decline']} onclick= history.go(-1); return false; /><input name= dle_rules_accept type= hidden id= dle_rules_accept value= yes /></form> );
}

Заменяем на:

} else {
//edit by FB
if( $config['allow_alt_url'] == yes )
$url = $config['http_home_url'].'register/';
else
$url = $config['http_home_url'].'index.php?do=register';

$tpl->set( '{ACCEPT-DECLINE}', <form method= post name= registration id= registration action= {$url} ><input type= submit class= bbcodes value= {$lang['rules_accept']} />   <input type= button class= bbcodes value= {$lang['rules_decline']} onclick= history.go(-1); return false; /><input name= dle_rules_accept type= hidden id= dle_rules_accept value= yes /></form> );
//
}

3. В файле engine/modules/register.php, ищем строчку:

$row['template'] = str_replace( {%validationlink%} , $config['http_home_url'] . index.php?do=register&doaction=validating&id= . $idlink, $row['template'] );

Заменяем на:

//edit by FB
if( $config['allow_alt_url'] == yes )
$url = $config['http_home_url'].'register/validating/{$idlink}/';
else
$url = $config['http_home_url'].'index.php?do=register&doaction=validating&id='.$idlink;

$row['template'] = str_replace( {%validationlink%} , $url, $row['template'] );
//

Далее ищем строки:

$tpl->copy_template = <form method= post name= registration onsubmit= if (!check_reg_daten()) {return false;}; id= registration action= . $config['http_home_url'] . index.php?do=register >n . $tpl->copy_template .
<input name= submit_reg type= hidden id= submit_reg value= submit_reg />
</form> ;

Заменяем это чудо на:

//edit by FB
if( $config['allow_alt_url'] == yes )
$url = $config['http_home_url'].'register/';
else
$url = $config['http_home_url'].'index.php?do=register';

$tpl->copy_template = <form method= post name= registration onsubmit= if (!check_reg_daten()) {return false;}; id= registration action= {$url} >n . $tpl->copy_template .
<input name= submit_reg type= hidden id= submit_reg value= submit_reg />
</form> ;
//

Ну и на последок, ищем строку:

msgbox( $lang['all_info'], $lang['confirm_ok'] . <br /><br /><a href= . $config['http_home_url'] . index.php?do=register&doaction=validating&step=2&id= . rawurlencode( $_REQUEST['id'] ) . > . $lang['reg_next'] . </a> );

Заменяем на:

//edit by FB
if( $config['allow_alt_url'] == yes )
$url = $config['http_home_url'].'register/validating/'.rawurlencode($_REQUEST['id']).'/nextstep/';
else
$url = $config['http_home_url'].'index.php?do=register&doaction=validating&step=2&id='.rawurlencode($_REQUEST['id']);
msgbox( $lang['all_info'], $lang['confirm_ok'] . <br /><br /><a href= {$url} > . $lang['reg_next'] . </a> );
//

Вот и всё.