1- download and extract flo-newkernel-2.zip
from https://github.com/ubports/ubuntu-touch/issues/300#issuecomment-450403133
2- after extracting , run the following :
fastboot flash boot flo-boot-new.img
fastboot flash recovery flo-recovery-new.img
3- download and install ubuntu-device-flash
wget https://repo.ubports.com/pool/bionic/main/g/goget-ubuntu-touch/ubuntu-device-flash_0.35+ubports+0~20181221200828.5~1.gbpd7daaa_amd64.deb
4- run the following for stable
ubuntu-device-flash touch --server=https://system-image.ubports.com --device=flo --recovery-image=flo-recovery-new.img --bootstrap --wipe --verbose
or the following for edge
ubuntu-device-flash touch --server=https://system-image.ubports.com --device=flo --channel=ubports-touch/16.04/edge --recovery-image=flo-recovery-new.img --bootstrap --wipe --verbose
HINT : may need to repartition following this guid
for 16GB nexus7 :
- System repartition
mkpart primary 2415919104B 3611296256B
- User repartition
mkpart primary 3678372353B 15020436481B