Has everyone given up?

yes

I haven't posted here yet, but I've been working on this for about 1/2 hour everyday & I'm still no nearer!

I would like to know now please

I think we pretty much have given up.

Here is my explanation of the clues - I cant see the other ways to do. But I must have been something wrong.... :/Soo it means that no more than 7 characters are changed in this code. But at the same time other 9+ characters could change their positions as well.Hmm.. that could have different meaning.
Hidden wording, some examples:
- SS = less
- XTR = extra
- CHNG = change
Direct signs, some examples:
- substraction (-)
- multiplying (X)
Hidden wording is less probable as it does not exist (I think) in second code. Direction could be understand as "left, right" or philosophically (example: you should go into math). I think this character could be 2, 4 but also -. I'm excluding number 8 and X.
I think I've tried all possibilities with 2, 4 and -, nothing... First part could be understand as:
a) SS-ULXT-RCHN-GAG824 - I cant see too much math here*
b) 84---4SSULXTRCHNGAG - There is math, but it does not work...
We could also move - to the end but it won't create anything different.

*) But I've still tried to subtract single letters, groups of letters etc...

So well... I think Iam just missing something because Im not too fluent in English and some wording of clues can have the other meaning as I think.

Heh, you are so close. Your only mistake is not paying full attention to the clue.

My explanation of the clues:

Clue 1 - pretty self explanatory.

Clue 2 - the only thing unchanged from the original code are the dashes/minus signs

Clue 3 - the dashes are different from the rest, indicate direction (down) and indicate that 3 characters are changed.

Clue 4 - throws me. Sounds like I need to move the dashes after the numbers or the letters and do the math... but I'm at a loss.

I tried many different ways.
8-SS2-ULXTRCHNG4-AG < Moving the dashes after the numbers, nothing.
SS-8ULXT-2RCHN-4GAG < Moving numbers after the dashes, nothing.
Most of what I tried were "letter - number of letters", but nothing.

I've tried with and without including the X as multiplication, too.

Well I am moving one class. For me one class is a group of characters which belong to this class.

Yeah, I don't see how you're missing the clue, because I'm missing that clue, too.

I do not think Xyem meant all characters of a class. At least that is not how I worked with that clue when I tried to solve it (the way Lexor did it does not yield a valid code format). Instead I tried to create a substraction or multiplication, but I did not get anywhere (i.e. to solution). What puzzled me for a while that 8 is the first of its four-letter portion of the code, 4 is second, X is third and 2 is fourth - they are all in different position and you could create an equation out of them - 4 X 2 = 8 but I could not fit this anywhere ot go anywhere with it...

P.S. I need to buy a new keyboard. This glass of Coca Cola I spilled into it last weekend was not healthy for it.

Then for me it should be like "move one character of one class". It says clearly "move one class", not anything else and one class is one class not "some of characters included in one class".

Maybe, but then you need to do something else in order to get a result in the valid code format.

Yes, but it could be like "move one class of character to after another class of character and then just.. do the math" and AFTER math move them back to starting positions. And I did that in many ways - nothing.

example in steps:

1) 8SS2-ULXT-RCHN-G4AG
2) 82---4SSULXTRCHNGAG - then do 82-(-(-4))=82-(+4)=82-4=78=078=O78 (as 0 cant be used)
3) then going back to starting positions: OSS7-ULXT-RCHN-G8AG

Go from here.