You can create a php file with below code in you magento setup root folder and execute in browser.

<?php
error_reporting(E_ALL);
ini_set('display_errors', '1');
require_once 'app/Mage.php';
umask(0);
Mage::app('default');

$products = Mage::getModel('catalog/product')
    ->getCollection()
    ->addAttributeToSelect("*");
foreach ($products as $product) {
    $product->setPriceShippment($product->getPrice() + $product->getShippment());
    $product->save();
}

You can create a php file with below code in you magento setup root folder and execute in browser.

<?php
require_once 'app/Mage.php';
umask(0);
Mage::app();

$products = Mage::getModel('catalog/product')
    ->getCollection()
    ->addAttributeToSelect("*");
foreach ($products as $product) {
    $product->setPriceShippment($product->getPrice() + $product->getShippment());
    $product->save();
}