My company is currently at a rebranding process and the brand names have been used in the sources' package names but these names are only visible to developers who maintain this code so nobody from project management is really interested in changing them considering also that it would imply the recompiling of several old components.

What factors do I need to consider when deciding on a change like that?

I don't know if I should worry about legal issues or not and if so, how to address this with project management.

_{More background details. I have all the sources and dependencies but since the company rebranding, other development areas have adopted some of the code that needs package name-changing so I cannot take the decision only by myself so I don't make everyone else's code to crash with my core components and I cannot change other areas' code without the permission of those areas' users so yes, my concern is more political than technical. I am going try to coordinate the involved it areas to make the change anyway, since it seems to be the best approach.
 
Unfortunatelly in my company there's no continuous integration build server so we build our code manually on demand and to get something to production I have to justify the change (even just the package name changing) to QA with an user requirement and some other bureaucratic documentation so that's why I was hesitating the change in first place.}