XSLT Basics For Transforming One Specific XML Structure To Another XML Structure

I was messing around with R (i.e., a free program that can organize and transform data), and I told R to transform the data into CSV format.  I converted this CSV format file into XML file using one of those CSV to XML free tools on the Internet.  The problem is that the XML file I got from the whole process contains structure in which is radically different from the XML structure that I need to use with a software.  Luckily, XSLT comes to the rescue.  With XSLT, I discover that it’s possible to transform one XML structure to another XML structure.  The problem is that I have no knowledge of how to use XSLT just yet.  Once again, YouTube is a treasure trove of free information, and the YouTube video right after the break introduces me to XSLT basics.  Of course, I may have to do more study and research on XSLT before I would know how to properly transform one XML structure to another XML structure.