Boxers who managed to adapt their style

[dookus]

Fury

[Matt W]

I think Ali is the obvious one, adapting his style in both a wider career sense, and significantly in an individual fight.

Barrera the obvious recent example that springs to mind (I say recent, his win over Hamed was 17 years ago which basically means I'm ancient).

Lennox Lewis successfully adapted under Emmanuel Steward into a much more complete boxer.