Well, it looks like the direct links to the service pack is gone since they switched to the "update" packs.

You will need the Autodesk Desktop App Updater. Note that you may have to reboot and then right click the icon in the task bar to update the actual updater client before it will show you the latest CADmep udpates.

https://knowledge.autodesk.com/search-result/caas/downloads/content/autodesk-application-manager.htm...