```bash
ln -fs /opt/ruby-enterprise-1.8.6-20090201 /opt/ruby-enterprise
ln -fs /opt/ruby-enterprise/bin/gem /usr/local/bin/gem
ln -fs /opt/ruby-enterprise/bin/irb /usr/local/bin/irb
ln -fs /opt/ruby-enterprise/bin/rake /usr/local/bin/rake
ln -fs /opt/ruby-enterprise/bin/rails /usr/local/bin/rails
ln -fs /opt/ruby-enterprise/bin/ruby /usr/local/bin/ruby
```