Change specific font in pdf document

I have a PDF file, which has a buggy font (some d's, o's and q's with black color fill inside the circe) which is annoying to read.

How can i change that specific font in the whole document, keeping the file structure?

PS: I am using GNU/Linux, so i prefer a cross-plataform solution.

You can try PDFedit, IIRC, it could change the font of a PDF, but it's QT3 based, so newer distros are removing it.

If you can't use that, try this one, i think it also had that capability.

If they fail, try other alternatives to Acrobat and PDFedit.