Hi,
the boot config file is usually installed to /tce/boot/extlinux
but that would depend on how you installed TC
try the find command
sudo find / -iname "*linux.conf"
which should spit out something like
/mnt/sda2/tce/boot/extlinux/extlinux.conf
Or if you installed with grub?? then use
sudo find / -iname grub.cfg
which may spit out something like
/mnt/sda2/tce/boot/grub/grub.cfg
You will likely need root privileges to write to the config file so use sudo