Have you followed the guide outlined by microsoft?
1.Download the Open Search Description (.OSDX) file. You can download a connector from the Available connectors list.
2.Import the file into the search solution by doing the following: In Central Administration, click Manage service applications, and then
click either the name of the Search service application (when you use
SharePoint Server 2010, Search Server 2010, or Search Server 2010
Express) or the name of your FAST Search Query Search Service
Application (when you use FAST Search Server 2010 for SharePoint)
where you want to add the federated location.
On the Search
Administration page, click Federated Locations, and then click Import
On the Import Federated Location page, browse to the .OSDX
file that you saved in step 1, select the file, and then click Open.
Click OK, and then click Done.
3.Connect the federated location to an end-user results page by doing the following: On a results page in the Search Center, on the Site
Actions menu, click Edit Page. Click the zone where you want to add
the Web Part, and then add the Federated Results Web Part, Top
Federated Results Web Part, or Core Results Web Part to the page.
Right-click the Web Part, and then click Properties.
In the Web Part
Properties panel, expand Location Properties, on the Location
drop-down list, select the location that you imported, and then click
OK. On the ribbon, click Stop Editing.
If you do not see the web part then you need to go to Site Collection Features to activate it ;)
go to Site Actions->Site Settings-> Go to top level site settings->Site collection features and Activate the Office SharePoint Server Search Web Parts feature.
hope it helps :)