HORROR: the removal of the oil dipstick

After I found some oil under the car, I looked under it and saw that both oil pans were leaking some oil. I badly needed to change the fluids anyway, so I ordered some new gaskets for both oil pans. Looking at them I though it was going to be a walk in the park. Draining the pans was easy. Then I removed the gearbox pan, and some balls fell out. I feared for the worst, but I didn't make any sense because the gears worked beautifully. After checking the old internet, it turned out to be some positioning balls for the gears. Luckily I was able to catch them while falling. So I had the gasket removed and basically did what Mr. Birdman said in one of his tutorials.

After that I tried to remove the engine plate. But it didn't came off. Again I checked on this and other sites and learned that the oil temp thing and dipstick had to be removed. The first one came off nicely. But then I wanted to remove the dipstick, and to be honest, I could't reach it AT ALL.

Now my question: is there ANY way to remove it without having to take off other parts? Is there any good way to do this? A normal 27 mm open wrench seems too large. Also the upper small nut (the one that holds the tube to the cam cover) is a nightmare. Should I take off the entire engine cover?

I already bought a 27, 24 and 10 mm wrench to make them a lot shorter, hopefully this helps...