How to edit the metadata information displayed by mdls from CLI?
The Spotlight metadata attributes are not stored in the files, but they are based on other metadata values or properties of the files.


ID3 tags can be edited from iTunes or with for example mid3v2 from mutagen
Modification times and creation times can be changed with touch or SetFileInfo
File flags like kMDItemFSIsExtensionHidden can be edited with chflags
kMDItemContentTypeTree depends on the filename extension
kMDItemLogicalSize depends on the size of the file


Changes to files are usually reflected in mdls output within a few seconds, but if they are not, try using mdimport.