Is it possible to convert .trn (transaction log) file to human readable form
I've used 3rd party tools in the past when it got too difficult to track down the log file modifications, especially as the file is minimally logged to mostly record the page modifications.  Here is a tool I've used, you can search for others if you like.  It has a functional free trial.  Sometimes I install these on a VM then remove it as it does tend to embed itself sometimes.

http://www.apexsql.com/sql_tools_log.aspx