The simplest path is to convert the project using Paratext 7.6 before migrating to PT 8.0, but the conversion can be done after migration. While it is called “conversion”, it actually creates a new project. When you are happy with how the project was converted, then you will have to delete the old project and remove it from the registry.
The convert function is found at Tools–>Advanced–>Convert project. It has a line with two boxes that says replace old name with new name. It will then replace the name everywhere it appears in the project history. I have never heard of problems with this part of the conversion. The issues I am aware of have to do with the normalization of the Unicode characters.
By the way, another common use of the conversion tool is to rename a project. It is desirable to use the ISO code as the name of projects, since this better identifies the project.