Make sure they lose in the general. The GOPe blurs the line of what Conservatism and liberalism are. They provide cover for the Dems and actively attack the Conservatives that they are supposed to side with. If you want to defeat the Dems, and their liberalism, first you must defeat the GOPe and its liberalism.
If we can't replace them in the primaries, then make sure they are replaced with a full blown liberal in the general. With out the GOPe providing the Dems cover, the LIVs will see them for what they and their policies truly are. It will be painful, it will be dirty, it will be what is needed to affect real change in this country; short of a shooting war.