The patch can be downloaded from Magento Tech Resources page and installed as usual bash script under Magento root directory:
$ bash ./PATCH_SUPEE-2629_EE_1.12.0.0_v1-2015-02-12-04-30-34.sh Checking if patch can be applied/reverted successfully... Patch was applied/reverted successfully.The following files are patched:
app/code/core/Mage/Catalog/Model/Product.php app/code/core/Mage/Core/Controller/Varien/Router/Standard.php app/code/core/Mage/Install/etc/config.xml app/code/core/Zend/Pdf/FileParserDataSource.php