Hi guys! I'm from Ukraine and I would like to translate all the dialogs into russian. to make a localized version. But I don't know where all the dialog files are, could you help me to find them and ''unrar'', if it's possible. Thanks

well the game is free on the scummvm website, if you need something to unrar it, try 7-zip it's a great free program for compression.

you see : all the data files are packed into SKY.DSK file, but i don't know how to open it

http://www.fileinfo.net/extension/dsk This should help you with your problem.

DSK files can be read by WinImage, or an IBM tool called LOADDSKF. IBM also has a similar command-line DOS utility called SAVEDSKF to translate the diskette to a dsk file.

To save you some energy, those tools probably CAN'T open the file. Just make a bet on the probability of a standard disk image versus a proprietary binary data file being found among the data files of a proprietary game program. :)
People on the ScummVM forums can most likely help you on your quest.

3rd one down in my link DSKE Simple IDs for opening data files saved in the .DSK format.

Data files that are "Database of ID cards created by Simple IDs, an identification card creator program", really? That description comes from the very same page.