How do I correct a 1099r

I have two 1099Rs for two Roth IRAs that I inherited from my Dad.  Both show a taxable amount for distributions that should not be taxed.  The code shows "4" for Death but should be "Q," I believe.  I have contacted my financial institution to get them corrected but they are having a hard time with it.  How can I correct my 1099R's myself, before 4/18?