[xwiki-users] Is it possible to upgrade a stand alone xwiki enterprise to version 2.2.3

I have a previous version (not sure which one anymore, but it is a few months old, not more) of XWiki Enterprise installed as standalone (my IT supplier is crap, I know) and I would like to upgrade to the latest version (i.e keeping the layout changes I made, which are light ones, but more importantly all the pages created already!). Is it possible? Thanks in advance, Xavier