Use sp_dropdevice to drop database and dump devices.
sp_dropdevice logicalname
You cannot drop a device that is in use by a database. You must drop the database first.
sp_dropdevice removes the device name from sysdevices. sp_dropdevice does not remove an operating system file; it only makes the file inaccessible to SAP ASE. Use operating system commands to delete a file after using sp_dropdevice.