Baby steps, I say. If you do the majority of the cooking, you can easily change a few tiny things, like using a little less oil/butter when you're cooking. I have a few sneaky tricks that I do to save money and cut down on calories.
(1) I gradually started to water down my juice along with the kids' juice. Now we're down to about 1/3 juice to 2/3 water, and drinking regular juice tastes like guzzling juice concentrate! We don't miss full-strength juice at all. I often will add a tiny bit of extra water to my husband's cup as well, but I haven't required him to jump on the watery-juice bandwagon. I've been thinking I'd start adding a little extra water to the pitcher, though.
(2) DH loves whole milk and says that 1% is gross. We compromised by going to 2%. But to save money, I started buying powdered milk to cook with. I buy the individual packages to make it easier to use, and because sometimes I don't use it very often and a big box can go bad/taste funny before I can use it up. I make pudding and mac 'n cheese (both homemade and boxed) with it, and anything else that the flavor will be masked in. And then whoops! The extra reconstituted milk just fell right into the milk jug! I have to be careful to not get more than half of it powdered milk, or DH says it's starting to turn. I've been doing this for nearly 3 years, and he still doesn't suspect! And because the powdered milk is non-fat, it lowers the fat content of all the milk we drink.
Another idea is to not completely deprive your family of the foods you love. Try out new recipes that are healthier and see if your family likes them. Pick out the healthiest meals from your usual repertoire and serve those more often than the "bad" ones.
My husband is also rather opposed to changing our food, even though he claims he wants to eat healthier. He says, "but fat TASTES good!" I've slowly weaned him down, and he doesn't complain about that anymore.
Besides reducing the resistance to change, baby steps will also help you make this a life-long change. Making a drastic change is a great way to fall off the band-wagon!