Ok,
so which OS version, Apache version and PHP version do you want to use with sablotron?
I read your other post about MySQL for Windows, so assuming that you want to activate sablotron on a Windows system (and that you already apache/IIS and php up and running):
1) make sure that there is a valid php.ini file in the windows (systemroot) directory
2) copy expat.dll, iconv.dll and sablot.dll from the zip php package to the system32 (or system on win9x/winme) directory
3) set the extension_dir configuration parameter in php.ini to the extensions directory of your php root dir (like e.g. c:\php5\ext)
4) uncomment (or add) the line extension=php_xslt.dll in php.ini
Thomas