Agree with Susan.  You can't because F.8879 specifically requires an SSN (for the original copy to be signed anyway) and does not provide for the use of TTIN.  I suppose that's to ensure that all digits in the SSN are verified by the taxpayer.

Here's more on the final regs: https://www.federalregister.gov/documents/2014/07/15/2014-16464/irs-truncated-taxpayer-identificatio...