Actually, there is no "work around" that will do things correctly. Either way you do it will end up with the exact same bottom line results (assuming you manually do the math correctly, which is not as simple as you think.). Just do no conversion at all, indicate the property was not rented all year then enter number of days a rental, and number of days personal use. The program will then do the splits for you.
If you don't let the program "do the work" the way it's designed to work, then in the tax year you sell the property, the TurboTax program will be unable to correctly report the depreciation recapture.
