I have set of sources and the respective resolution. Please advice how to resolve the same using Unix shell scripting.

Source 1:
=======
<ext:ContactInfo xmlns:ext="urn:AOL.FLOWS.Extensions">
<ext:InternetEmailAddress>AOL@AOL.COM</ext:InternetEmailAddress>
</ext:ContactInfo>

Resoultion 1:
=========
< InternetEmailAddress>AOL@AOL.COM</InternetEmailAddress>

Note 1
=====
Tags with ContactInfo should not come on to Target and ext: should be removed through out the Source.

Similarly

Source 2:
=======

<e
xt:InternetEmailAddress>

(Or)
<ext:Conta
ctInfo xmlns:ext="urn:AOL.FLOWS.Extensions">

Resolution 2
=========
<InternetEmailAddress> - ext: splitted across multiple lines should be removed, this can be splitted across any number of lines also

Source 3
=======

<IFeed>
<Organization>
<Participant>…
<ParticipantName>..</ParticipantName>
<ParticipantId>…</ParticipantId>
</ Participant>
</ Organization>
</IndicFeed>
<IFeed>
<Organization>
<Participant>…
<ParticipantName>..</ParticipantName>
<ParticipantId>…</ParticipantId>
</ Participant>
</ Organization>
</IFeed>

Resolution 3
=========
<IFeed>
<Organization>
<Participant>…
<ParticipantName>..</ParticipantName>
<ParticipantId>…</ParticipantId>
</ Participant>
<Participant>…
<ParticipantName>..</ParticipantName>
<ParticipantId>…</ParticipantId>
</ Participant>
</ Organization>
</IFeed>

Here I got some "quick fixes" to two of your problems:

Prob1:
++++++
$ cat source1.xml
<ext:ContactInfo xmlns:ext="urn:AOL.FLOWS.Extensions">
<ext:InternetEmailAddress>AOL@AOL.COM</ext:InternetEmailAddress>
</ext:ContactInfo>

$ cat source1.xml | sed '/ext:ContactInfo/d'
<ext:InternetEmailAddress>AOL@AOL.COM</ext:InternetEmailAddress>

Prob3:
+++++++
$ cat source3.xml
<IFeed>
<Organization>
<Participant>.
<ParticipantName>..</ParticipantName>
<ParticipantId>.</ParticipantId>
</ Participant>
</ Organization>
</IndicFeed>
<IFeed>
<Organization>
<Participant>.
<ParticipantName>..</ParticipantName>
<ParticipantId>.</ParticipantId>
</ Participant>
</ Organization>
</IFeed>


The idea is to remove the all "Organization" tags except the 1st and last one. Similarly the "IFeed". Here we go

----
#!/bin/sh

#this function will remove all instances of any tag (except 1st and last)
f_remove() {
count=0
RMVPARAM=$1
grep -n "$RMVPARAM>" source3.xml | awk -F ":" '{print $1}'| sed -e '1d' -e '$d' | while read lnum
do
num=`expr $lnum - $count`
echo $num
sed "$num d" source3.xml > source3.xml.tmp
mv source3.xml.tmp source3.xml
count=`expr $count + 1`
done
}

f_remove Organization
f_remove IFeed
---

Now

$ cat source3.xml
<IFeed>
<Organization>
<Participant>.
<ParticipantName>..</ParticipantName>
<ParticipantId>.</ParticipantId>
</ Participant>
</IndicFeed>
<Participant>.
<ParticipantName>..</ParticipantName>
<ParticipantId>.</ParticipantId>
</ Participant>
</ Organization>
</IFeed>

%%</IndicFeed> can be removed directly, if not required :-)

//Jadu