so can't use ftp and have installed latest drush in ln -s /usr/local/share/drush/drush /usr/local/bin/drush
then navigated back to root directory of my drupal site and typed in drush in command line and hey presto
it listed commands.
Then i typed in drush update because i have some modules needing updating and i was hoping it would just detect and update but
i must have wrong command because says update command cannot be found.