Use vinegar. As an acid it can cut through the calcium. May take some time, wrapping in a rag wet with vinegar etc. Assume that the hoses won’c come off the washing maching plastic solenoid fittings. Try backing them with a pair of channelock pliers. If the problem is on the supply valves, do the same. One pair of channelocks on the valve to keep it from turning and one on the brass hose connection. Remember that less is more. Do not squeeze on the hose connections any more than you have to to get a grip. Good luck.
If all else fails, use a hacksaw to cut through the edge of the hose connection, just to the threads of the faucet. You will be able to see when you get to that point and then use a thin chisel or screwdriver to separate the cut and loosen the hose.