How to remove printing restrictions from PDF?

Nowadays, it is very common and convenient for people to download PDF files from websites for life or work. But sometimes, when we want to do some editing or printing of PDF files, difficulties arise - we are restricted and therefore cannot do such operations. The reason is that, for reasons of data security and privacy, etc., PDF files are protected with permission passwords. In the face of this trouble, many people will wonder whether there is any way to solve it. And to our relief, the answer is yes. In this article, 3 different ways will be elaborated to provide a complete tutorial to remove printing restrictions from PDF files.