Conversion of long-existing SEP IRA to Roth

I've seen a how-to for entering the conversion of a traditional IRA immediately to a Roth (i.e., a backdoor conversion), but I need help ensuring that I can enter the conversion of a long-existing SEP IRA (containing only pre-tax (i.e., deductible) contributions) to a Roth IRA.  

 

How do I enter it?  I know I will pay taxes on the entire converted amount.

 

TY