The term is "converting" to a ROTH not a rollover so when you ask the broker to do it they know what you are doing and put in the correct paperwork.
As to the how much ... that is hard to say exactly since it depends on your 2016 income & the 2016 tax brackets. Best thing you can do is mock in a tax return when the programs are available later this month or next month then make the conversion by 12/31/16. If you find you converted more than you wanted to you have until 4/17/17 to undo all or part of the conversion... that is called a recharacterization.
Tax tables are on page 44 ... https://www.irs.gov/pub/irs-pdf/p15.pdf