You need get familiar with documents first.
Check Jetson TX1 Developer Kit User Guide about recovery mode.
Check http://docs.nvidia.com/jetpack-l4t/ to find how to download.
http://docs.nvidia.com/jetpack-l4t/content/developertools/mobile/jetpack/l4t/2.3/jetpack_l4t_install.htm
Get Uart log to find if system is booting normally.