1. download the all the files from the original server.
2. export the db using to a sql file.
3. upload the files to the new server.
4. create mysql db and new db user in the new server.import the exported sql to the newly created db.
5. edit the configuration.php. modify the user/dbname/password to the new ones.
6. if you have a php.ini, do remember to remove it or rename to php.ini.backup. otherwise 500 internal error will be waiting for you.
Step 5 and 6 is the part we tend to ignore and forget.