With this small change will improve the functioning of the clutch.
 

For instructions, click the link below.

KAWASAKI KLX250

Adding a washer to slightly increase the spring tension. It will only make any difference if your clutch springs are weak or the friction plates worn. In both cases you're better off replacing the worn parts since to add the washers you have to pull the entire clutch assembly down that far anyway.

Is your clutch slipping?

Inserting the washers is how to mount the shorter springs,
the control lever of the clutch becomes softer,
the engine is hot, the clutch opens without friction.
To insert the washers do not need to remove the clutch,
but just unscrew the six screws.
The clutch does not slip because the measurement of 0.5 mm washers
is less than the service limit of the clutch spring.

Clutch spring free length
Standard: 35.4 mm (1.39 in.).
Service limit: 33.9 mm (1.33 in.).

You indicated position clearly shows that removal of the front of the clutch assembly is required.
You did not mention shorter springs, not did the post you linked to.
If you somehow reduce the pressure from the springs on the clutch plates you are reducing the ability of the clutch to transfer torque to the transmission.
What you are telling people to do is NOT going to help anything, you can't even get the basic mechanical operation of the clutch right.
If you want a lighter fee to the clutch get an after market clutch lever with a different leverage ratio or just try lubricating your clutch cable once in a while rather than screwing around with something you clearly do not understand.

The clutch on the klx works fine from stock no need to screw with it at all.

op didn't really state which direction he was shimming? you can shim the bolts and make the clutch pull lighter, or shim the spring and make the clutch hold stronger.

Dosen't really matter when there is no problem there to begin with.

Stock clutch is fine with stock bore.

There's also a guy that lengthens the clutch lever arm (down by the case) for KLR650 bikes. This gives a lighter feel and provides more slipping control for off road riding.