How would you handle a situation between a few workers relating to a power they believe they hold over minorities in the work place?

Situation- I was once assigned as a product manager for an information solutions app. This product was called hub and would be an API on top of which custom platform development can be made. One of the most important stakeholders were the legacy data team. This was a small team but held tremendous control over the data feed coming from their applications which in turn would be source for the new set of APIs being developed

Task- My task as a product manager was to work with the legacy team member to develop few interfaces on their side so as streamline development of the API. The legacy team were difficult to work with since one, this new API would reduce billing for the legacy app thereby resulting in loss of jobs and second, it would be additional workload for them to support development of this API.

Action- I started meeting this team on a daily basis. For the first few days, we did not even discuss work, it was all about knowing each other. After that, I started off explaining my needs then talking to them about my requirements. This helped them plan the best way to help me without creating large disruptions on their day to day schedule. This was followed by  leveraging the leadership team to talk to them and alleviate their concerns about job loss. There were other team building exercise used to create icebreaker between this team.

Trust and transparency went a long way strengthening relationship with this team. Also, their perspectives were given importance as part of feature development.

Result- The initial few months were tough, once the team felt that we were not a risk to them and intention was not load them with additional tasks, the team was extremely supportive of our efforts