I think you should give them a chance to get in line with your other clients. 80/20 principle and all, Get rid if they take up a disproportionate amount of your

I think you should give them a chance to get in line with your other clients. 80/20 principle and all, Get rid if they take up a disproportionate amount of your time vs the revenue they bring in. Drop them a mail, inform them that your rates have changed, new working conditions, expectations, turnaround time etc details should be attached also. Clearly outline the working process should they wish to keep working with you. If they can't agree to the new conditions you'll be happy to refer them to other consultants. You might be surprised that they start to be easier to deal with. I guess it all depends on how much you want to keep them.