Cashed in IRA early to pay off student load, how to I enter this in Turbo Tax

You simply enter the 1099-R.  There is no 10% penalty exception for paying a student loan.   The educational exception is only for educational expenses paid to a qualified school during the same year as the distribution.

Enter a 1099-R here:

Federal Taxes,
Wages & Income
(I'll choose what I work on - if that screen comes up)
Retirement Plans & Social Security,
IRA, 401(k), Pension Plan Withdrawals (1099-R).

OR  Use the "Tools" menu (if online version left side) and then "Search Topics" for "1099-R" which will take you to the same place.

Be sure to choose which spouse the 1099-R is for if this is a joint tax return.
Be sure to pick the correct 1099-R type: Standard 1099-R, CSA-1099-R, CSF-1099-R, RRB-1099-R.

[NOTE: When you get to the "Your 1099-R Entries" screen where you can add another 1099-R, use "continue" to keep going as there are additional interview questions after that screen in most cases. You can always return as shown above.]

If you have received a Form 1099-R, enter the information here:

In TurboTax online, 

• Sign in to your TurboTax account and select Pick up where you left off
• At the right upper corner, in the search box, type in "1099r" and Enter
• Select Jump to 1099r
• Follow prompts

An early distribution from an IRA does not fall into one of the exceptions to waive the penalty.  Therefore, you will be subject to a 10% penalty.