You may transfer the money from your 401k account to the Roth IRA - that transaction
is classified as conversion. The amount you will convert - will generally be taxable - so if you plan such conversions - you may spread them over several years to avoid large taxable income
and higher tax brackets in any single year.
As you will be 70 1/2 on Nov 15, 2015 - according to current laws - you will be required to have RMD for 2015. But only for your 401k plan and traditional IRA. You will determine the amount of RMD separately for each account.
You will need to use Uniform Lifetime tables for 2015 that are not available yet.
But assuming these tables would not change - we may use 2012 tables for estimates.
Because your wife is 12 yrs younger then you - we need to use Table II - started on page 95
The combination of your and your spouse ages will be 70 and 58 - Joint Life and Last Survivor Expectancy would be 28.8.
Assuming - you will have $300,000 in your 401k plan on Dec 31, 2014
Then your 2015 RMD amount would be $300,000 / 28.8 = $10,417.
You will be required to take that distribution before April 1, 2016.
Let me know if any clarification needed.
Please be sure that tables might slightly change - and actual percentage could be a little different.