It should be as simple as opening the project using RoboHelp 11.
Always make a backup for our friend Justin though!
Should be? I'm looking for something more concrete than that! How about a guarantee it will work.
LOL. Nobody is going to give you that and if they do, don't believe them. We don't have any way of knowing everything that you may have done in your project. As Rick has indicated you just have to create a backup and see what happens and with one exception, as the man says it should be that simple. Create your backup as a zipped file so that you cannot accidentally open it but you can keep extracting the content if you need to.
The exception might be lists. They changed in Rh8 and what you may need there is described on my site.
See www.grainge.org for RoboHelp and Authoring tips