Well, this is never pleasant, but I've been down this road before. Step one is to turn the water off, open the flush valve, and look down into the tank from the toilet. If you are looking at a dried mass, you are going to have to get the mess rehydrated and maybe even get some decomposition rolling, depending on your time frame. If it's dried up, fill it with water and let is sit for a few days. This might be enough to get things moving. Or, If you are getting a bit of liquid flow out of the valve, the next step would be to buy a wand and use it. A wand is a flexible shaft that attaches to a garden hose and allows you to probe the tank from the toilet opening and by poking and blasting water out the end of the wand, it will often loosen up. If this all fails, fill the thing to the top, add some Rid-ex septic tank additive and give it a week or two. In warm weather, with a lot of water in there, everything will eventually decompose to a nearly solids free brown soup. Good luck, and don't forget to wear some disposable gloves. Any cuts on the hands ,and shit water are a bad combo.
