I am sure that a mixture of RNAse and a drop of alkaline phosphatase or commercial 5'-nucleotidase in a buffer around pH8 will be able to transform your RNA in a mixture of nucleosides. If the enzymes are not perfectly purified and you add some phosphate you may even obtain some bases. In fact often, commercial nucleotidase or phosphatase  preparation contain also some nucleoside phosphorylases. Good luck