I'm making Russian localization for the Roshpit Chanpions, so first of all I must to say that the first translation of the entire text is the most difficult. Then it will be easier to do updates.

• Willpower - Today Roshpit Champions have over 9.7k rows of text, that wait to be translated.
  
• GCFScape - Program to extract original addon_english.txt Nem's tools download page[nemesis.thewavelength.net]
  
• Notepad++ or similar text editor

If you have all of those options - let's begin!

• Launch your GCFScape.
  
• In GCFScape hit CTRL+O and open .. \ steamapps \ workshop \ content \ 570 \ 469311655 \ 469311655.vpk.
  
• Go to the / root / resource / folder then find and extract filehttp://imgur.com/TUeatKD.
  
• Make the copy of this file and rename the copy like "addon_LANGUAGENAME.txt", depending on the language in which you will create the translation. For example: "addon_russian.txt", "addon_swedish.txt" or "addon_romanian.txt" etc.
  
• Start translating
  
• Change the 3rd row ("Language" "English") to your language name.
  
• Translate the text in second quotes in every possible line except for the skills, runes, weapons, items and glyph names, because its better for community.
  
• Make sure, that all quotes are at their place or your file will be broken in the game.

When you'll done, upload yout localization file to somewhere like Google Drive and send the link to ChalkyBrush.

Now you should have another one program, that can help you find the difference between updates.
I use "TextDiff[www.angusj.com]" because its easy and useful, but you can find Notepad++ plugin with same potential.

• Rename old addon_english.txt to something like "000addon_english.txt"
  
• Launch GCFScape and open again *.vpk file, extract new addon_english.txt
  
• Rename new addon_english to something like "001addon_english.txt"

Now you can compare both files. Start TextDiff and hit "File - Open file 1" or CTRL+1, then open old "000addon_english.txt"
After that hit "File - open file 2" or CTRL+2 and open new "001addon_english.txt" file.
Then you should hit "Actions - Compare" or "F9" button and click on down arrow icon to move to the next difference[imgur.com].
Remember the row number. Open your old translation and new addon_english.txt in notepad++, on your file make right click and hit "Move to other view[imgur.com]"
After that, click on two locks[imgur.com] for lock horizontal and vertical synchronize of both text fields
Find the row, that TextDiff showed us and make the change.

When you've done with all changes, save file and upload to the same place as before and send link to ChalkyBrush

• All modifiers tooltips, that starts like DOTA_Tooltip_modifier_... should have "%%" after the number
  (e.g.: "DOTA_Tooltip_modifier_voltex_rune_b_a_description" "Your attacks have a 15%% chance to unleash a powerful Chain Lightning")
  But sometimes you can see 3 percent signs in a row, because %property_#% have their own "%"
  (e.g.: "DOTA_Tooltip_modifier_ivory_gryffin_aura_effect_Description" "Magic and Pure damage reduced by %property_two%%%")
  
• In main abilities descriptions you can use some HTML tags like <font color='#70EA72'></font> or <br>.
  
• In items descriptions you can also use <br> tag to start from a new line.
  
• If you need to make new line in main abilities, use \n tag without any quote.
  
• If you need to add quotes into translation, use single 'quotes' instead of "double"

This guide can be updated soon.