Help reset to fresh wallet and channels

I have a rP4 with ver 1.0.4 installed. I want to wipe an old setup that crashed and has not been used for a few years.
I tried the instructions from the problem FAQ
sudo systemctl stop umbrel-startup && sudo rm -rf ~/umbrel/lnd/!(lnd.conf) && sudo rm ~/umbrel/db/user.json && sudo rm ~/umbrel/db/umbrel-seed/seed && sudo systemctl start umbrel-startup
But I get an error
Failed to stop umbrel-startup.service: Unit umbrel-startup.service not loaded.