Its easy to upgrade wordpress from 2.7 to 2.7.1 this tutorial for manual upgrade:
- Download the latest wordpress http://wordpress.org/download/
- Extract them to your own folder
- Connect to your server via ssh or ftp client and backup wp-config.php and wp-content/themes, wp-content/plugins
- Upload your extract file to the server replace ALL
- Restore your backup wp-config.php, wp-content/themes, wp-content/plugins
- Done
- Note for your save please backup your database first but I do this step and succesfully