This is exactly what I did. I opened up the patch folder. I ran deltaX GUI I chose the right patch i needed (black or white). I chose my rom (which was already patched with the EXP thing from way before). I clicked apply patch. I got my new rom and it was named (W/e it was named before)_PATCHED.nds
I am using windows 7 I have that .net framework thing installed
I even patched it again with the new patch when i got it.