Firstly make a copy of your front end and back end databases.
With your copies you can do one of two things
1. Keep your database split and use the Linked Table Manager to change the table links in your front end so that it links to the copy of your back end .mdb
or....
2. In your front end delete the linked tables in the database window and select File, Get External Data and Import... and you can import the tables and their data from the back end .mdb
Hope this makes sense