Switching my cats from free feeding to scheduled feeding: need advice!

I have two cats, Missy (10 YO) and Chevy (4 YO). Missy has been having issues with going to the bathroom recently and was taken into the vet. We found out she had bladder stones. She passed one on her own but was taken into surgery to have two more removed. Everything went wonderful and she returned home today. 

We now have a new issue on our hands - Missy must be placed on the Hills prescription diet in order to maintain a healthy bladder to ensure she does not have any more crystals develop. Chevy is just fed Purina indoor cat chow. Both cats used to eat this food and were free fed. Since the prescription diet is so expensive (about $60 for a bag) I would like to only have to feed it to Missy. The only way I can think we could successfully do this is by having each cat on a scheduled feeding time. 

I was hoping that I could get some advice on the best ways to begin feeding the cats on a scheduled time. 

Start giving them the amount of food you want to feed at that meal and leave it down for 15 to 20 minutes. You may have to place them in separate rooms to start. It will take patients if they are not used o it and they will be angry. But they will learn. You may also want to consider switching her to canned if she has stones. Those foods don't really do what they should in dry forum.

First hello and welcome to TCS.

Here is a recent post with some helpful information. http://www.thecatsite.com/t/259664/canned-food-for-bladder-stones

Switching them to scheduled feedings is a great start and can be difficult at first. But the best thing you could do for them is switch them to a wet diet. Water is so important for cats with urinary problems and for all cats in general. They just don't get enough on dry food. That post has links to explain this further. Can you get the canned version of that prescription diet?

I suppose I should have mentioned that Missy is on the wet food diet with her new prescription diet. She will have wet food with a mix of dry food. We are having the stones looked at in a lab and will hear back from the vet whether we should continue with wet food or if he thinks the dry will be fine for her. Chevy gets wet food twice a week, but she does not have bladder issues. 

We have the types of food figured out for now for both types a cat. It is more just a matter of switching them to a different feeding method. 

The attached article is actually on how to transition your cat from kibble to canned, but in it it discusses moving from free feeding to a schedule, AND also discusses Urinary Tract Problems, so it's kind of the best of both worlds for you!  Hopefully you'll find it helpful:  http://www.catinfo.org/docs/TipsForTransitioning1-14-11.pdf