# Option 2: Unzip the CMSIS-Pack (Advanced Users)

Advanced users might need to modify the linked library and system files to suit their needs. If so, they can take advantage of the fact that the CMSIS-Pack is a zip file with an xml descriptor (.pdsc file). The CMSIS-Pack can simply be unzipped, independent of an IDE. Then the files can be taken directly from the unzipped output and modified as necessary. When new CMSIS-Packs become available from onsemi, the updates need to be manually copied/merged.