I am not a cue maker but this subject has been discussed. I can't find the link for that thread but I believe the answer was you have to send it to an authorized repair person to have any work done. Not doing so will void the warranty.
From what I remember reading, a joint swap is probably going to be more trouble than it is worth due to the construction method and materials used. You have very little to no room for error and risk destroying the shaft.
If it were me, I would have somebody make a mid cue extension with both joint types used so you can screw the butt and shaft into the extension.