You can repack .xz files (XZ Utils archives) to WinZIP archives (.zip) using PeaZip or any other file manager or archiver utility with support of both these compressed archives. Should be pretty straightforward process, it's just XZ format is not that known or supported.
Convert XZ Utils compressed archive to WinZIP Compressed ZIP archive.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert xz to zip on Windows
A free open source archive utility
Convert from xz file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.