Use a tFlowToIterate after the tFileInputRaw. This will store the byte array in the globalMap HashMap with the key "row.column" (replace row for the row name and column for the column name leaving the tFlowToIterate). Then connect from the tFlowToIterate to the tRest using the Iterate connector. Once this is connected, set the Http Body field to the value held by the globalMap. It will look something like below....
((byte[])globalMap.get("row.body"))
You will also need to set a header in the HTTP Headers section. The header name is "Content-Type" and the value will likely be "application/octet-stream".
This should work, but there is always a bit of jiggery pokery required when sending files via web service.
Oh, the HTTP Method will likely be POST.
