This example code will convert xml to a new xml structure using XmlTransform alias.
 string xsl = @"<xsl:stylesheet version=""1.0"" xmlns:xsl=""http://www.w3.org/1999/XSL/Transform"">
   <xsl:output method=""xml"" omit-xml-declaration=""yes"" />
   <xsl:template match=""/"">
     <xsl:for-each select=""pastery/cake"" >
         <price><xsl:value-of select=""@price""/></price>
       </xsl:for-each>
   </xsl:template>
 </xsl:stylesheet>";

 string xml = @"<?xml version=""1.0"" encoding=""UTF-8""?>
 <pastery>
     <cake price=""1.62"" />
 </pastery>";

 var priceTag = XmlTransform(xsl, xml);

Result:

<price>1.62</price>