Decompress
.odt and .docx files are .zip files. You can try to decompress them as if they were regular .zip files.
If that doesn't work, you can change the extension from .odt or .docx to .zip and then decompress the file.
Compress
Compress the folder to a .odt or .docx file.
If your zip program doesn't allow to compress to .odt or .docx, you can compress to .zip and then change the extension to .odt or .docx.
Note: You don't have to compress the directory with the decompressed files, you have to compress the contents of the directory. Thus, the compressed file will have in the root the meta files and directories, and not the directory that contains the meta files and directories.