For the tiny nut on the bottom I simply *gently* use some small Water Pump Pliers....
For Diesel cars, the sender often has fungus lurking inside it and it's easy to take apart and clean if *VERY*DELICATE* .
Use some small delicate pliers to pinch the soft plastic surround protecting the special nut and unscrew it then it all comes apart easily .
Work over a clean light colored cloth and use electro - contact cleaner or aerosol starting fluid to clean the funky black fungus ~ you need to get every bit of it out, use a soft toothbrush on the bottom part .
Test easily by tipping the sender up and down with the plug attached and the key on .
7.17.2016 ~ I don't see any how to for the park brake shoes.....-Nate
You'll find it wise to use a toothbrush sized wire brush to clean the calipers where the pads go while it's all apart .
Pretty good Tech Tip .
It's _VERY_ important to change the power steering fluid any time it's not red color or sweet smelling .
If it's brown or you can't see through it , change it every oil change until it remians translucent ~ failure to do so will cause pum leaks or failure .
Use ATF , _never_ power steering fluid .