Wordpress update theme with new pages, also swap out images

I need to update my existing Wordpress, including all of the new pages, while keeping the existing content. I also have existing images that need to be swapped out as part of the update you will need to supply royalty free ones the text I will update myself. The scope of the project is to update the theme and replace certain images with new ones. I'm looking for a Wordpress expert to help make sure the job is done properly and quickly. I have paid for and installed consulting theme with demo data, however I have quite a few pages created that need to sit under the NEW theme once complete all old data and plugins not required should be removed
please do not apply if you cannot commit to working through sometimes on the fly this is not a large job as most of the work has been completed its more tidying up