How to be user-centered with enterprise solutions?

I work in a large organisation with a culture shift to configuring enterprise solutions, buying solutions or building sofware - if no options are available.

In my experience, enterprise solutions have notoriously bad UX and cannot be easily changed to meet users needs and are often considered based on a feature checklist over user goals. This is sometimes compounded by no consideration to the total cost (UX Debt, productivity etc), just perceived savings (money).

Does anyone have any experience/advice on implementing a user-centered Design Process or techniques with configured or bought enterprise software?