Update existing WordPress website to latest theme version

General information for the website: Existing theme
Kind of development: Customization of existing website
Description of every page/module: All, from existing site
Description of requirements/features: Install latest version of theme and make existing content compliant. No additional design or content required
Specific technologies required: Wordpress
Extra notes: This is a simple job for someone with WordPress experience.

The present website is running on an out-of-date version of the theme. I need it updated to the latest responsive version of the theme, which will be supplied, retaining all existing pages and content. Once updated and fully compliant, suggestions from the contractor will be welcome for improvements to the site structure.

All relevant details will be supplied:
Address and login details; Theme zip file including ALL theme documentation and XML files

Edit – For those seeking clarification, here are more details:

Existing site: www.smarthinking.com.au
Existing theme: MediaConsult v1.0 by Goldenworks
Update to MediaConsult v3.8