As far as I know, it is possible, but you will have to perform some manual operations, like editing the code of your kprx to change all the references to the former name. I think I would copy/paste the kprx in Visual Studio, in order to get all the sub-projects copied too (the famous ExtenderProjects), exclude the copied process from the project, edit the files with a text editor to change all the references, and add the process again ("add existing item").
I think I will go to the file system where I store my k2Projects. There I have a folder "Process1! with the .sln file and so on. Then I will create a new Folder "Process1new" and copy all the files from the folder "Process1". And when I open then the .sln from "Process1new" I can rename the solution, the project and the workflow process. But I think nevertheless I have to do some manual operations in the kprx because there are still some paths to the old "Process1".
Oh!! You're cheating!! You create a new project, it's easier
Yeah but you're right, if having everything in the smae project is not a requirement.