I hope this will help you:
Reflection.Assembly TxAssembly = Reflection.Assembly.GetExecutingAssembly();
Stream stream = TxAssembly.GetManifestResourceStream("Reports.MyReport.rdlc");
reportViewer1.LocalReport.LoadReportDefinition(stream);
or
reportViewer1.LocalReport.ReportEmbeddedResource = "Reports.MyReport.rdlc";
Important is full path to your report file within EXE file.