When your map is protected, MPQ editor will show it as read-only.
There are complex ways of deprotecting that depends on the protection used. Here I will just give a simpler method that might make a few custom ui missing but on the whole map should work. This method is extracting all the files and add them to a new unprotected mpq.
While that sounds simple, extracting the file is kind of useless without knowing its name, because if you reimport it with a random name it won't work. So this method involves finding out the names of the files... aka name breaking. MPQ Editor has a name breaking feature if you go to tools -> w3x Name Scanner
After clicking there, just hit the first scan button and it will try to find out the names. This can take even an hour depending on how protected is the map. When that is done, you will have several options of what to do with the name list.
Choose Save List and put save it wherever as ladik.txt, usually in same folder as your map is a good choice. You could apply this list and then extract the files directly with MPQ Editor but that doesn't work well on some maps so better use my tool.
Run node scripts/findListFile.js yourwc3map list.txt folderPath ladik.txt where yourwc3map is the path to your w3x, list.txt is the path to where you want to store the name list, folderPath is where you want to extract the files and the rest of the parameters are optionally additional name lists to consider (as my tool also does name breaking in another way). Between ladik and mine, you should have most of the useful files found and extracted.
With this we can build a new mpq. Copy Empty map somewhere and then use MPQ Master to open it (not sure if MPQ Editor doesn't support adding files from directoy or I never found how). Right click and choose add Directory
Choose the folder where you extracted the files with previous command and when it finishes just close window. Now your map has all the files and you can rename it. Open it with mpq editor and finally add the translated files to it.
It is possible some maps featuring new protections work with mpq editor but not my tool. In these cases, you will have to extract the files manually from mpq editor.
Same as before, open map in mpq editor, do name scanner, but hit Apply List instead of Save List. You should see files with names now. Click on name to order by name desc and see if there are many unknown files. These appear in the format File00000xxxx.
Unknown files can either be fake files, unused files (both cases we don't care) or a file the map needs, which we will lose without figuring out the name. This case it very rare, as name breaking works very well to detect files mentioned in script/related files. The most common case of missing file names that are actually used is maps that modify standard wc3 files such as UI. As they are standard, wc3 loads them by default and thus are not mentioned in any map file, so name breaking can't recover them. This is fixable by adding a listfile with all standard wc3 files paths. This can be made from the standard wc3 files, but you can just download it from zezula. As this is different in each wc3 version, it might still be missing some names you need, but should cover most cases. With this you can click on add list file and select the right file.
Now select all files and folders (click first, scroll to bottom, hold shift and click last) then right click and hit extract.
These files go to your work path, which is something like xxx\Ladiks MPQ Editor 32bit\Ladiks MPQ Editor 64bit (v3.5.1.814)\Work. If you already did this with a map before, its good to first remove all files there before extracting. Once all is extracted, go the folder and delete all files that were left as unknown, which are in the format name File00000xxx (this is not needed but will reduce the size of the map, don't want to add useless files).
Then Use mpq master as before to make the new map with these files and your map is ready.