dbWindow 3.0 removes all the stumbling blocks to using a database with MicroStation

As you can see, there are several options in the Graphics pull-down menu. You need to download dbWindow 3.0 to try all the powerful features.
The Detach Linkages command allows you to define which linkages to detach instead of detaching all database linkages indiscriminately. The command also lets you choose to delete the graphic element from the design file, or delete the database record, or any combination of these options.
There are five ways to define which elements to process.
Single allows you to datapoint each element individually if a selection set is not defined.
Selection Set processes all elements in a selection set.
Fence processes all elements matching the fence criteria.
Global processes all elements on all levels in the design file.
Multiple Files allows you to define a list of files / directories and process all elements on all levels in each of the design files.

The Detach Database Linkage dialog allows you to define which linkages you wish to detach from MicroStation elements. Simply move the table names that correspond to the linkages you wish to detach from the Available list to the Selected list. The Selected list determines which linkages are detached.

There are four options with this command.
Detach linkage(s) on element only removes the linkage(s) from the graphic element.
Delete element(s) with linkage(s) will delete the graphic element from the design file.
Delete database record(s) and detach linkage(s) on element will remove the database records from the database as well as detaching the linkage(s) from the graphic element.
Delete database record(s) and element(s) will remove the database records from the database as well as deleting the graphic element from the design file.