Install D8

Install D8

download
unpack (12330 files)

create sites/default/files
copy services.yml
copy settings.php
change settings file

 $settings['trusted_host_patterns'] = array(
   '^www\.example\.com$',
 );
replace 
'^www\.example\.com$',
with your site address
'^d8\.cord\.no$',

upload
change
chmod a+w sites/default
chmod a+w sites/default/files
chmod a+w sites/default/settings.php

after install
change
chmod go-w sites/default
chmod go-w sites/default/settings.php
chmod 644 sites/default/services.yml

Result:
sites 755
sites/default 555
sites/default/files 666
sites/default/services.yml 444
sites/default/settings.php 444

run cron

Set site to maintenance mode while develop
admin/config/development/maintenance
enable Put site into maintenance mode

To avoid loosing of bartik theme
admin/config/development/performance
BANDWIDTH OPTIMIZATION
disable Aggregate CSS files