If the remote database is being access by Character Clients, then all you need is a telnet client and a login. Then it will depend on the licenses they have available there and the setup. If they have a Query/Report or development license, you could use those to do ABL queries or use the Results report writer.
Otherwise, you need either Client Networking or SQL Client on your own machine for ABL and SQL queries respectively. If you are going the SQL route, it is necessary for the other end to have set us SQL access first. If they are already doing SQL reporting or whatever locally, then piece of cake, otherwise a bit more work.
Given a SQL setup at their end, you can also use things like Crystal Reports.
A lot depends on what they have setup, what you want to do, and what you know.