How to migrate Database from 5.0.1 to 6?

We are having an issue migrating all of our data from 5.0.1 to 6. The sql_upgrade script does not work correctly. When we also try to simply use the 5.0.1 database with the version 6 code things break. Can anyone assist us with this issue. We are willing to pay for the service.

This might help: Upgrade v502 to v600 10% per hours