just wondering if taking off the heads and putting them back on my 98 GT going to be a pain in the butt or not. this will be my first time messing with the motor in my car. i've done everything else to it myself and kind of want to learn more about the motor. how long does it take for a first timer? after i get them off, i'm having a shop do new valves, etc. so all i have to do is take them off and put them on. will this take me a few hours or a few days?