Parse the XML, remove the parts you don't want with removeChild (in 2.0a at least) and then save the resulting XML.

I've never use the function remove child, have you some example about it syntax?

Example to test with Processing 2.0a8+:

1. String s = "Inside tags, you will find <tag>multiple</tag> " +
2.     "<tag>pieces</tag> of <tag>content</tag>.";
3.  
4. XML xml = XML.parse("<x>" + s + "</x>"); // Real XML must have a root node
5. XML[] tags = xml.getChildren("tag");
6. for (XML tag : tags)
7. {
8.   xml.removeChild(tag);
9. }
10. println(xml);
11.  
12. exit();

Using regular expressions on XML might work in simple cases or on XML whose content you know, but it is prone to problems in the general case. For example, one can put a </tag> in a CDATA section inside a <tag> text: it is valid, but it should be ignored when removing these.

Thank you so much, I have to learning fast and example are usefull for me, since I'm not expert in syntax.

The linked thread isn't about XML...

In your code snippet, you mix two things.
xml_0 is holding already parsed XML.
XML.parse with my trick with an x tag is to parse a simple string like the one you provided.
You can avoid this trick, I think, since s is holding a tag and its content.

Will come back later for more tests.

Now, if regular expressions works for your needs, go on, but just be aware that in some cases, it might not give what you expect.

Yes, I also found inside the text some paragraph formatted with "==" before and after, and i'm using it to divide it in parts.

Another little question:

String inAngleBrackets = "\\{\\{.*?\\}\\}";