Here is an example of how to create a component via OSLC:
1) GET /rm/oslc_config
2) In this document, find the oslc:ServiceProvider entry, it should be something like <server>/rm/oslc_config/components
3) GET on the URL found in step 2
4) This gives you the service provider document.  In here you need to find the oslc:CreationFactory entry.  On my server the URL is /rm/cm/component/ldpc?project=<UUID>.  You will have one of these entries for each project area.
5) POST to the appropriate URL from step 4 for the project area where you want to create a component.
Request headers:
OSLC-Core-Version: 2.0
Content-Type: application/rdf+xml

Request body:

<rdf:RDF
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:jfs="http://jazz.net/xmlns/foundation/1.0/"
    xmlns:acc="http://open-services.net/ns/core/acc#"
    xmlns:rmTypes="http://www.ibm.com/xmlns/rdm/types/"
    xmlns:process="http://jazz.net/ns/process#"
    xmlns:rmWorkflow="http://www.ibm.com/xmlns/rdm/workflow/"
    xmlns:dcterms="http://purl.org/dc/terms/"
    xmlns:dc="http://purl.org/dc/elements/1.1/"
    xmlns:h="http://www.w3.org/TR/REC-html40"
    xmlns:xs="http://schema.w3.org/xs/"
    xmlns:oslc="http://open-services.net/ns/core#"
    xmlns:oslc_config="http://open-services.net/ns/config#">
    <oslc_config:Component>
        <dcterms:title rdf:parseType="Literal">Create Via OSLC</dcterms:title>
        <dcterms:description rdf:parseType="Literal">Test description</dcterms:description>
    </oslc_config:Component>
</rdf:RDF>

You can do a GET on an existing component to see an example representation.