First mount the necessary filesystem directories.
mount /dev/xvdb1 /mnt mount -t proc none /mnt/proc mount --rbind /sys /mnt/sys mount --rbind /dev /mnt/dev chroot /mnt /bin/bash
list current kernel:
grubby --default-kernel
check available kernels:
ls /boot | grep vmlinuz
change to different kernel:
grubby --set-kernel /boot/vmlinuz-kernel-version