On the desktop, on the printer properties page, select the sharing tab and share the printer.
You may also need to install the printer drivers on the laptop. One way of doing this is to connect the printer to the laptop just for this purpose.
Then with the printer connected to the desktop you should be able to see the printer from the laptop (e.g. in Settings, Printers and Faxes) and either select it as the default or select the printer from within your applications when printing.