BLOCKREPLACE command
The BLOCKREPLACE command can use one block to replace another one, moreover, you can purge the unreferenced block when the operation is finished.
Command Access :
Menu : Express tools>Blocks>Replace Block
Command Entry : BLOCKREPLACE.
Select a block to replace: Double bed. Then select : OK
Select the block to be replaced: Sofa. Then select: OK
Purge unreferenced items when finished? Yes/No
See the result below: