Remove 'Import Contacts' from SugarCRM

1. Go to directory: sugarcrm\custom\Extension\modules\Contacts\Ext\Menus
   (Create the directory if you already don't have one)
2. Create a file: menu.ext.php
   
Write the below code in that file

foreach ($final_module_menu as $key => $val){
if($val[1] == $mod_strings['LNK_IMPORT_CONTACTS'])
unset($final_module_menu[$key]);
}

If you check the file sugarcrm\modules\Contacts\Menu.php, you can see the code for all menus that are seen in Action Menu of contacts.

$final_module_menu is the array which contains all those values:
$final_module_array =
Array (
    [0] =>Array ( [0] => index.php?module=Contacts&action=EditView&return_module=Contacts&return_action=index [1] => Create Contact [2] => CreateContacts [3] => Contacts )
    [1] => Array ( [0] => index.php?module=Contacts&action=ImportVCard [1] => Create Contact From vCard [2] => CreateContacts [3] => Contacts )
    [2] => Array ( [0] => index.php?module=Contacts&action=index&return_module=Contacts&return_action=DetailView [1] => View Contacts [2] => Contacts [3] => Contacts )
    [3] => Array ( [0] => index.php?module=Import&action=Step1&import_module=Contacts&return_module=Contacts&return_action=index [1] => Import Contacts [2] => Import [3] => Contacts ) )

So comparing $val[1] with the value of the item we want to remove, gives the required $key value.

After making any changes in the file, go to Admin->Repair->Quick Repair and Rebuild. This will execute the code.

Note: Sugarcrm Version - Sugarcrm 6.0.2