It took me about 3 hours, if you have the right tools and vacuum with little pipe and read instruction manual, it would take less time. I got 10 years mechanic engineer background in China. I never tried HVAC, I paid a guy with 30 years experience $500 to replace a zone panel in attic after letting young guy to repair, he quoted me $1000 to replace an electronic panel, it is 2 years house, so I called another HVAC guy to spent half fixed it. I think you can try if you like to take challenges and like to repair, youtube teaches a lot of repairs.