At the risk of sounding sarcastic, I would say a mechanic. I am having to replace the one on my 96 Explorer and its a PITA. Everyone that said they would do it, backed out, and the ones that did come to do it didn't have the right tools, and the one they needed, we couldn't find. (9/16" half moon wrench)
With tools
Knowledge, tools and pizza
on the 3100V6 you will find the PCV valve on the valve cover (front valve cover...closer to the radiator) on the drivers side of the cover, there is a hose attached to it. this will be on the OPPOSITE side of the pulleys, it is directly in the top on the valve cover. and slides out with no tools needed
If it is a 1.9L it takes a box or open end wrench in 10mm to take the 2 bolts off in the center of the valve cover.
You have to drop the transmission pan and then drop the valve body. Make sure you remember or have the manual to know what bolts go where when you drop the valve body. Then you push in the detent valve in the middle of the solenoids and the keeper for the valve will come out and the valve will come out also.
if your talking about the oil seals that go around the valve stems, you can do it with some specialized tools. But if your talking about removing the valves which include the stems then your going to have to pull the heads to get them out.
Get the 2004 Ford Etis. No special tools required but wiper arms and the cowl panel grill must be removed before. Also mind that a software update can be needed if you drive an early C-Max..
on the front of the engine, to the right of the eng oil fill cap. the only hose there. pull out and replace in same direction. no tools needed.
No tools required pull valve from valve cover, pull valve from vacuum line, install new valve.
What kind of valve?
Yes. Check with your local auto parts store for the necessary tools.
You will have to remove the evaporator from underneath the dash on the passenger side. If you have the right side tools it is not a difficult job. This will require you to first evacuate your A/C system. I would recommend changing the evaporator along with the expansion valve.