Programming Xilinx XC9572
If the security fuse hasn't been blown, you can read the configuration of the chip out over JTAG with a suitable adaptor and access to the right pins.  You can then programme that into another chip of the same sort (check the speed-grades are the same) using the same interface.

If the fuse is blown, I'm not sure the JTAG interface can be used for anything much.

This monster search on Xilinx's site might point you to some useful info...