Install multiple Sybase ASE 15 instances on the same Windows server

I'm not able to find any official documentation on installing and configuring multiple Sybase ASE 15 servers on the same Windows server. Basically, we already have an ASE instance running on a Windows server. It runs a tiny database. For business reasons, we need another copy of the database. But the vendor is lazy and their scripts have the database name hard coded, forcing us to install another ASE instance just to host that tiny database. We'd like to install this second instance on the same Windows server.

But I have not been able to find Sybase documentation on how to do this. Any help is appreciated.