I have retrieved the test plans, testcase out using rpe 1.2 from rqm 4.0, How do I retrieve the testscripts steps for each testcase?

I believe you are using RQM reportable RESTful API to retrieve all the artifacts. You cannot get testscripts steps directly within a test case. You must obtain the test scripts within a test case, then obtain test script steps within each script.

To find the url for test scripts within test case, find an element named "testscript" like below within the obtained test case xml:

<ns2:testscript href="https://davidbox-win7:9443/qm/service/com.ibm.rqm.integration.service.IIntegrationService/resources/Quality+Manager/testscript/urn:com.ibm.rqm:testscript:1"/>

Then use the url in href attibute with a param to do another GET of the test script:

https://davidbox-win7:9443/qm/service/com.ibm.rqm.integration.service.IIntegrationService/resources/Quality+Manager/testscript/urn:com.ibm.rqm:testscript:1?etlmode=true

or

https://davidbox-win7:9443/qm/service/com.ibm.rqm.integration.service.IIntegrationService/resources/Quality+Manager/testscript/urn:com.ibm.rqm:testscript:1?abbreviate=false

You will find entried in returned xml like:

<ns2:steps><ns9:step ns1:id="_KmLf0bbNEeKZePXMCv2ntw" type="execution" stepIndex="1"><ns9:name>1</ns9:name><ns9:title>1</ns9:title><ns9:description><div:div xmlns:div="http://www.w3.org/1999/xhtml" xmlns="http://www.w3.org/1999/xhtml">1</div:div></ns9:description><ns9:expectedResult><div:div xmlns:div="http://www.w3.org/1999/xhtml" xmlns="http://www.w3.org/1999/xhtml">1</div:div></ns9:expectedResult><ns9:comment/><ns9:compare/></ns9:step></ns2:steps>

Wish this helps.