If I filed my last year return with tax form 8332 and I need to include that same form on my current turbo tax return, how do I attach the 8332 form to my e-file return?

 If you are filing your return electronically, you must file Form 8332 with Form 8453, (U.S. Individual Income Tax Transmittal for an IRS e-file Return). See Form 8453 and its instructions for more details.

This must be done within 3 days of your e-filed return being accepted by the IRS.
http://www.irs.gov/pub/irs-pdf/f8453.pdf

The 8453 is also included in TurboTax.  Use the search topics box to find it.