Toyota Repair: 1991 toyota previa le, heater control valve, 1991 toyota previa

Question
Need to replace a heater control valve (leaking occassionally).

Any suggestions as to what steps to take first. I am concerned about losing the coolant once I disconnect the 2 hoses.

Answer
Replacing the heater core is quite a project so I would recommend getting a repair manual that shows step by step instructions. Sorry, I misunderstood you to say you wanted to replace the core, the valve is easy to replace and is located under the hood, just get a couple of plastic plugs that fit into the hose ends and the coolant will stay in the hoses, you can get some rubber caps to block off the metal core pipes,