Make documentation clearer.

doc/install/installation.md

@@ -370,7 +370,7 @@ Make sure to edit the config file to match your setup:
     # domain name of your host serving GitLab.
     # If using Ubuntu default nginx install:
     # either remove the default_server from the listen line
-    # or else rm -f /etc/sites-enabled/default
+    # or else sudo rm -f /etc/nginx/sites-enabled/default
     sudo editor /etc/nginx/sites-available/gitlab
 
 **Note:** If you want to use HTTPS, replace the `gitlab` Nginx config with `gitlab-ssl`. See [Using HTTPS](#using-https) for HTTPS configuration details.

doc/reply_by_email/README.md

@@ -10,9 +10,18 @@ In this example, we'll use the Gmail address `gitlab-replies@gmail.com`. If you'
 
 ### Installations from source
 
+1. Go to the GitLab installation directory:
+
+    ```sh
+    cd /home/git/gitlab
+    ```
 
 1. Find the `reply_by_email` section in `config/gitlab.yml`, enable the feature and enter the email address including a placeholder for the `reply_key`:
 
+    ```sh
+    sudo editor config/gitlab.yml
+    ```
+    
     ```yaml
     reply_by_email:
       enabled: true
@@ -24,11 +33,15 @@ In this example, we'll use the Gmail address `gitlab-replies@gmail.com`. If you'
 2. Find `config/mail_room.yml.example` and copy it to `config/mail_room.yml`:
     
     ```sh
-    cp config/mail_room.yml.example config/mail_room.yml
+    sudo cp config/mail_room.yml.example config/mail_room.yml
     ```
 
 3. Uncomment the configuration options in `config/mail_room.yml` and fill in the details for your specific IMAP server and email account:
 
+    ```sh
+    sudo editor config/mail_room.yml
+    ```
+
     ```yaml
     :mailboxes:
       -
@@ -66,6 +79,10 @@ In this example, we'll use the Gmail address `gitlab-replies@gmail.com`. If you'
 
 5. Edit `/etc/default/gitlab` to enable `mail_room`:
 
+    ```sh
+    sudo editor /etc/default/gitlab
+    ```
+    
     ```sh
     mail_room_enabled=true
     ```