Corrosion on transformer leads, how serious?

[sameal]

So i have corrosion on the leads coming off my transformer.
How serious is this condition in performance?
Can i replace them without rewinding the transformer?
Im not sure i can rebuild a transformer, it sounds fun, but i dont have the experience.

 

[Whoops]

Post so pictures so members can see the actual damage and give advise based on that

 

[sameal]

I had a photo in my transformer troubles thread, but on my phone it has vanished. When i get back home ill get another snapshot.