Assuming the database URL you posted is not real and you are using the Helloku Shared 9.1 Beta addon (https://postgres.heroku.com/blog/past/2012/4/26/heroku_postgres_development_plan/), which is the only common database that allows you to connect from the outside, you just split into the appropriate parts.
Postgres: // sfbywaqhvj: _WgTgP660aDnYuS3aP3o@ec2-23-21-64-4.compute-1.amazonaws.com / sfbywaqhvj
becomes
Username: sfbywaqhvj password: _WgTgP660aDnYuS3aP3o host: ec2-23-21-64-4.compute-1.amazonaws.com database: sfbywaqhvj
source share