" No one listed the easiest option? Place a CV starter block. Spawn the desired base. Use the Build menu (N) to select and copy the entire base. Hit the Deselect button. Select a block on the CV starter using the build menu selection Hit Paste twice to paste the base onto the CV. Boom. The base is now a CV. No editing of files. No screwing around. No tutorial videos needed. 100% success rate. Takes about 30 seconds and you don't need to leave the game to do it." As stated by Vermillion This is by far the easiest way I have found to do this. Simple and easy to remember too!
I know it is a very old post, but I'll still post it here in case some1 will look for this very simple solution as I did lately. It's basaically a visual representation of the above reply. here's a detailed guide on how to copy the blueprint over the CV starting block. It does work. I created my first CV by hand - copied a wreckage I found in desert by hand Wish I knew this way back then Cheers!