Need to reconfigure FPGA on NIOS developement kit

Iam having NIOS developement kit Startix edition. When i put on the power supply it goes to preconfigured bit stream is activated.Even after removing flash and eventhough we program the new sof in FPGA.Due to this the LEDs are continuously glowing.could you help me how to burn a standalone RTL on to this board(FPGA)..