You can copy a linked model to create multiple instances in the host model.
For example, in the following image, building 2 and building 3 are copies of the same linked model.

To copy a linked model to another project file
Clipboard panel
Windows panel
Switch Windows drop-down, and select the project name to copy the linked model into.
Clipboard panel
Paste drop-down

If you want to edit the pasted linked model, click Edit Pasted Elements. See Editing Pasted Elements.