These Two Valve Spring Compressors are very similiar and will work on the TIII 16v or the Standard 8v Head with the head ON or OFF the car. If used with the head ON the car, (the KD 3087 is the better of the two, because the handle can be adjusted to use at 90 Degrees) you will need a compression tester hose that will thread into the spark plug hole, to pressurize the cylinder. Then rap the valve spring retainer using a deep well socket and hammer to break the seating of the keeper in the VSR. Install Valve Spring Compressor tool per pics below and remove keepers/retainers.
Note: The Brown Tube shown in the last two pics does not come with the tool. I made that up from a piece of 5/8" OD stock that I had laying around and then drilled 3 holes in it. With the 3 Holes, it will work in all locations and permit working on two valves at one location.

TIP: IF a air compressor is NOT available and the head is on the car; Remove the spark plugs. Turn the crank to lower the piston in the cylinder you are working on. Feed approx 2-3 feet of nylon rope into the cylinder (leaving some rope sticking out of the spark plug hole), Then BY HAND, turn the crank to raise the piston as high as possible. This will cause the rope to come in contact with the valve and hold it in the closed position while you work on the valve spring retainer assembly.