Rascal,
Best way to get fescue, or rye grass, or crabb grass out of bermuda is to spray your yard with Roundup. NOTE: YOU CAN ONLY SPRAY ROUNDUP WHEN THE BERMUDA IS DORMANT!!! Right now bermuda is dormant, it doesn't start growing until the end of April.
I have a house I'm working on. It is Bermuda sod in the front and fescue in the back. Nothing has been done to this yard since it was built (1998). This past weekend I sprayed the front with Roundup, and 2-4-D in the back to kill off the broad leaf weeds. Fescue is active so you can't spray it with Roundup. You have to spray with it's wamer than 65 degrees and won't rain for 24 hours.
Don't know where you are, I'm in N. GA, and as I said, Bermuda goes active at the end of April.
Hope this helps.
Bill Cook