Convert BLOCK to XREF
Replace all instances of a standard block with an xref. Unbind xrefs that are bound.
Menu: Express>Blocks>Convert Block to Xref
Command Entry: BLOCKTOXREF
BLOCKTOXREF searches the entire drawing for references to a specified block name and replaces them with an XREF that you specify. You can have the unreferenced block purged when done.
In BLOCKTOXREF dialog box. Select a block to replace: Table and 4 chairs. Then select: OK
In Select a Xref file. Select the Xref you want. Then select: open
Purge unreferenced items when finished? Yes/No