1. Go to the official site and download the forum source here:
http://download.simplemachines.org/

and the language you need is here:
http://download.simplemachines.org/?smflanguages;lang=russian
(Only you need to be careful when choosing an archive with a language – there are different encodings)

2. Then, we place it all on our hosting.

3. Then, following the guidelines http://wiki.simplemachines.org/smf/Installing
create a database and a user (you can do this in the console, or – in phpmyadmin):

mysql -u root -p
CREATE DATABASE forumdb;
GRANT ALL PRIVILEGES ON forumdb.* TO "userdb"@"localhost" IDENTIFIED BY "pass";
FLUSH PRIVILEGES;
EXIT

4. Unpack the forum in the target folder on the server:
mkdir /var/www/forum.example.com
cd /var/www/forum.example.com
tar -xzvf smf_2-0-x_install.tar.gz
tar -xzvf smf_2-0-y_russian.tar.gz (or smf_2-0-y_russian-utf8.tar.gz)

5. Create and edit a configuration for Apache:
nano /etc/apache2/conf.d/forum.example.com.conf

<VirtualHost *:80>
ServerName forum.example.com
ServerAlias www.forum.example.com
DocumentRoot /var/www/forum.example.com
<Directory "/var/www/forum.example.com">
AllowOverride All
Order deny,allow
Allow from all
AddHandler application/x-httpd-php .php .html
</Directory>

6. Verify the configuration and start the installer:
We check whether the configuration file was made correctly:
apachectl configtest
if there are no critical errors – gently restart Apache:
apachectl graceful
Now open your forum in the browser:
http://forum.example.com/install.php

7. Next – follow the instructions of the web installer.

8. Done!