HI agluck,
<CTRL> + <C>, then <CTRL> + <V>
Copy, paste.
Photoscan generates a folder called [projectname].files and a PSX file when you save a project. That's why you have to make sure to copy both the files folder and the PSX file for each project.
Note that your imagery is NOT stored in the files folder. If you copy/paste the files-folder & PSX file you can open the project and see what you have computed in PhotoScan (e.g., DEM, dense point cloud, etc), but you cannot reprocess the dataset unless you re-link the original pictures (which can be stored somewhere else).
Regards,
SAV