uh ehh whu what? you mean get the autoflowering genes from the ruderalis and put into another species of plant? becuase thats been done, do you know where you are right now? if you mean remove the gene from ruderalis, so you have non-autoflowering ruderalis, why would you want to?
Umm . . .there already is such a plant and its called "hemp".
From a genetics/breeding standpoint, crossing ruderalis with non-ruderalis plants to remove the autoflowering trait would be relatively easy. I won't get into the details of how to do it, but its basically the same thing as introducing the autoflowering trait into a non-auto line, only in reverse.
But why on earth would any breeder want waste their time removing the most useful feature of ruderalis strains to recreate worthless hemp plants?