Slave PUMS .dct file

Hello, I am trying to open the 1860 Flat Sample from SlavePUMS and cannot for the life of me figure out how to edit the .dct file. I googled solutions for mac, but I could not find anything helpful (a number of forums suggested QuickXpress, but that did not work). Does anyone know how to edit the .dct file to be able to extract the 1860 data?
Thank you,

I think my Stata must be glitchy because now it’s willing to open and edit .dct files when it was not before. So, problem solved!