I am having problems in Indesign CS6 on a mac. When I change a spot colour in the swatch window to process I can not go back and change the swatch back to spot, i get a message that the swatch can not be edited. I do have eps files placed in the document with the same spot colour but dont want to have to go to all my placed eps files and change them to process. I beleive in older versions of indsign you could change back and forth without the swatch getting locked.
In the Swatches Panel there's a sub menu in the panel - top right.
In here is the "Ink Manager"
You can selec the Spot Colour to be 4 colour process here.
And if you tick the Use LAB values at the bottom it would be best.
Talk to your print provider before continuing though.