Ubuntu upgrade (14.04.3) and solr upgrade (5.3) breaks solr3/jetty setup

Question

While upgrading our production server to ubuntu 14 the solr/jetty broke. To fix i tried: - upgraded java version to 8. - upgraded solr to 5.3

My earlier config used .war files. realized that now its stopped supporting .war files, so now cannot use my earlier config.

This was the steps i used earlier: copy the solr.war file from the downloaded and untarred solr to the webapps folder, and make jetty owner:

sudo cp ~/x/apache-solr-3.6.1/dist/apache-solr-3.6.1.war /usr/share/jetty/webapps/solr.war
sudo chown jetty:jetty /usr/share/jetty/webapps/solr.war

create a context file in JETTY_HOME/contexts (sudo vim /usr/share/jetty/contexts/solr.xml)

<?xml version="1.0"  encoding="ISO-8859-1"?>
<!DOCTYPE Configure PUBLIC "-//Mort Bay Consulting//DTD Configure//EN" "http://jetty.mortbay.org/configure.dtd">
<!-- Set the solr.solr.home system property -->
<Configure class="org.mortbay.jetty.webapp.WebAppContext">
  <Call name="setProperty" class="java.lang.System">
    <Arg type="String">solr.solr.home</Arg>
    <Arg type="String">/usr/share/solr</Arg>
  </Call>
</Configure>

tell solr how many cores we have and what those are in SOLR_HOME (sudo vim /usr/share/solr/solr.xml):

<solr persistent="true" sharedLib="lib">
 <cores adminPath="/admin/cores">
  <core name="demo" instanceDir="demo" />
  <core name="dev" instanceDir="dev" />
  <core name="qa" instanceDir="qa" />
  <core name="www" instanceDir="www" />
 </cores>
</solr>

etc.

Don't want to use the solr instance that comes with rsolr (4), if i can help it. But can't find corresponding info for solr 5.3

Running rails 3.2.21. and solr_sunspot gem 2.2.0

Thanks in advance!