Open you MySQL client
select * from core_config_data where path = 'web/unsecure/base_url' or path = 'web/secure/base_url';
You will get a list of your URL's
mysql> select * from core_config_data where path = 'web/unsecure/base_url' or path = 'web/secure/base_url';
+-----------+---------+----------+-----------------------+--------------------------+
| config_id | scope | scope_id | path | value |
+-----------+---------+----------+-----------------------+--------------------------+
| 496 | default | 0 | web/unsecure/base_url | https://www.domain.com/ |
| 497 | default | 0 | web/secure/base_url | https://www.domain.com/ |
+-----------+---------+----------+-----------------------+--------------------------+
Update the values you want like this
update core_config_data set value = 'http://www.example.com/' where config_id in (496,497);
Where your config_id is the value's from the column under config_id
If you find that this value = 1 you should change it to 0
select * from core_config_data where path = 'admin/url/custom';