If you really want to use Xampp, it's not that easy and requires some linux knowledge:
a) download the source code of php ming package
b) download and install the so called "Development package" of Xampp (i.e. http://www.apachefriends.org/download.p ... 8.1.tar.gz
c) open a terminal and compile and install the ming package; you must do that in a "xampp shell", there should be a kind of "xampp_sh" or something in /opt/lampp/bin. The xampp shell sets environment variables so that the "configure" and "make" commands for ming compilation yield to the appropriate header and include files.
If you never did an installation from source on a linux system before, it might be quite difficult to you.
I think, that it is by far easier NOT to use xampp, instead install Apache, MySQL and PHP which comes with your linux distribution (for example Ubuntu). If you do so (and have a debian based installation) you simply can install php ming via apt-get:
sudo apt-get install php5-ming
See also http://php.net/manual/en/ming.setup.php