Dietary care for a cat with liver disease will include high quality protein. Cats with liver problems should not be given shellfish, organ meat, or foods containing fish meal. These contain purines which metabolize to form uric acid, something the cat's damaged liver cannot process.
I got that from one of the links I have given you below. That said, here is what I learned as a child from an old woman who used to "vet" for people's pets. If you are currently medicating with liquids, it will be similar. If not you will need a couple of supplies.
First, get as much information as you can on the appropriate diet for your cat. The links I have given you will give you a good idea about the kind of high protein low fat food you can make. There are also a lot of nutritionally complete recipes that you can search for, and some have recipes specifically for kidney issues. Then, get some kitty vitamins, and while these don't have calories, it will make sure she is getting nutrients.
Next you will need a smallish flexible rubber tube, generally known as an aspirator, or a needle-less syringe. In your blender, blend your 3 oz. protein meat, the vitamin and 1/4 cup water. Add 1 tbs sugar or Karo syrup. Then, add about 1/4 cup more water until it is very liquidy (hold extra until needed). Take about a teaspoon of the liquid and add a pinch of Metamucil and a half a pinch of baking soda and fill up the syringe. Start with about about a teaspoon in the syringe or aspirator. The meat will give her protein, the sugar will give her carbohydrates (and help soothe the tummy), the baking soda will help keep stomach acids at bay, and the Metamucil will give her a non-grain easy to digest fiber. If she will take any food on her own you can give her this a few laps at a time.
You may want to get some help or get a towel to restrain her, but with her stomach on the floor (do not put her on her back or hold her like a baby), open her mouth (this is usually the really hard part) and squirt a few drops on the back of the tongue if you are not used to using a liquid med on your cat, because you want to make sure she doesn't choke. The back of the tongue should also be enough to make her swallow. Do this as many times as you can until you have gotten as much or all of the liquid as you can. Right now her stomach might be on auto-vomit, so you want to dose out the food in small bits. If she can start keeping the food down, you can use a little less water in the recipe and give her a higher dosage. Hold off on the anti-vomit medication for a while or wait until she has a little sustenance in her tummy.
Will this work on your cat? I don't know. Will this replace the need for a feeding tube? I don't know. My advice would be to seek out the services of a vet or qualified technician who can do this, but since you asked about force feeding, and that is the information I am giving you.
I hope it helps.