Thread:Project:Support desk/Upgrade (Mediawiki 1.15 XAMPP)

Hi. I need help from somebody smart. I have Mediawiki 1.15 install through XAMPP. After a lot of days I finally import my database to XAMPP (v3.2.1) (previosly I used MOWES). But I have very old MediaWiki (v 1.15) and I need to upgrade. But I'm completely lost in all the instructions and manuals. Please, please, can somebody help me step by step? Thanks.