create a copy of the current run.sh and call it "debug.sh" (or whatever other name you may like) and look for the current like that starts with this:
JAVA_OPTS="$JAVA_OPTS -Dprogram.name=$PROGNAME
and replace it w/ this:
JAVA_OPTS="$JAVA_OPTS -Dprogram.name=$PROGNAME -classic -Xdebug -Xnoagent -Djava.compiler=NONE -Xrunjdwp:transport=dt_socket,address=8787,server=y,suspend=y"