Streamline the CE to EE upgrade guide

doc/update/ce-to-ee.md

 # From Community edition 6.0 to Enterprise edition 6.0
 
+This guide assumes you have a correctly configured and tested installation of GitLab Community Edition 6.0.
 
 ### 0. Backup
 
@@ -19,25 +20,18 @@ sudo -u git -H RAILS_ENV=production bundle exec rake gitlab:backup:create
 
 ```bash
 cd /home/git/gitlab
-sudo -u git -H git remote set-url origin https://gitlab.com/subscribers/gitlab-ee.git
+sudo -u git -H git remote add ee https://gitlab.com/subscribers/gitlab-ee.git
 sudo -u git -H git fetch --all
-sudo -u git -H git checkout -t -b v6.0.0-ee
+sudo -u git -H git checkout 6-0-stable-ee
 ```
 
-### 3. Run bundle
-
-```bash
-cd /home/git/gitlab
-bundle install
-```
-
-### 4. Update config files
+### 3. Update config files
 
 * Make `/home/git/gitlab/config/gitlab.yml` same as /home/git/gitlab/config/gitlab.yml.example but with your settings.
 Note: Under LDAP settings fill in `group_base` setting.
 * Make `/home/git/gitlab/config/unicorn.rb` same as /home/git/gitlab/config/unicorn.rb.example but with your settings.
 
-### 5. Install libs, migrations, etc.
+### 4. Install libs, migrations, etc.
 
 ```bash
 cd /home/git/gitlab
@@ -51,20 +45,19 @@ sudo -u git -H bundle install --without development test mysql --deployment
 sudo -u git -H bundle exec rake db:migrate RAILS_ENV=production
 ```
 
-### 6. Update Init script
+### 5. Update Init script
 
 ```bash
-sudo rm /etc/init.d/gitlab
-sudo curl --output /etc/init.d/gitlab https://raw.github.com/gitlabhq/gitlabhq/6-0-stable/lib/support/init.d/gitlab
+sudo cp lib/support/init.d/gitlab /etc/init.d/gitlab
 sudo chmod +x /etc/init.d/gitlab
 ```
 
-### 7. Start application
+### 6. Start application
 
     sudo service gitlab start
     sudo service nginx restart
 
-### 8. Check application status
+### 7. Check application status
 
 Check if GitLab and its environment are configured correctly:
 
@@ -76,11 +69,13 @@ To make sure you didn't miss anything run a more thorough check with:
 
 If all items are green, then congratulations upgrade complete!
 
-## Things went wrong? Revert to previous version (6.0)
+## Things went wrong? Revert to previous version (Community Edition 6.0)
 
 ### 1. Revert the code to the previous version
-Follow the [`upgrade guide from 5.4 to 6.0`](5.4-to-6.0.md), except for the database migration 
-(The backup is already migrated to the previous version)
+```bash
+cd /home/git/gitlab
+sudo -u git -H git checkout 6-0-stable
+```
 
 ### 2. Restore from the backup: