Copyright rules

I’ve bought a module, and it wasn’t perfect, So I decided to improve that.
I think that is excellent now, and I want to sell that.
Does it violate copyright rules?
My code is 30% similar to the original module.

No, you are not permitted it. and by doing this your account can get permanently suspended. Thanks

I’ve added several new basic options to the original module and designed it with an almost new look, and it does not look like it.
Can the problem be solved by changing the same code and reducing the similarity of the code?

you will not be permitted at all. and the original author can send you DMCA (copyright notice) through envato support.