to install it, upgrade the uboot/openSBI if your card is on /dev/sda, it 
will place a backup of the current uboot in uboot.backup
##############################################################################
*** THERE IS NO HDMI OUTPUT FOR NOW ****. You need to use serial or network
(wifi (LicheeRV dock/MangoPI WiFi mnaged) or ethernet (via USB or hardwired)
to connect to the board
##############################################################################
=====================
DEVICE=/dev/sda
# Backup
dd bs=1024 skip=128 count=1024 if=${DEVICE} of=uboot.backup
# Write uboot
sudo zstdcat u-boot-sunxi-with-spl.bin.zst | dd bs=1024 seek=128 of=${DEVICE}
# Mount disk, write mainline kernel next, umount and sync
sudo mount ${DEVICE}2 /mnt
sudo mount ${DEVICE}1 /mnt/boot
DIR=`pwd`
(cd /mnt; sudo tar xf $DIR/linux-6.2.0-rc8-next-20230217.wireless.tar.zst)
sudo umount /mnt/boot
sudo umount /mnt
sync
=====================

You can simply boot again on previous kernel by renaming in /boot:

mv extlinux extlinx.disable