This can be done using the mkps command (this invokes mklv with the correct options).

 1. enter mkps -a -n -s size vgname (where size is in Physical Partitions -
    size of which can be checked with lsvg vgname ).
 2. can check with lsps -a
 3. To mirror enter mklvcopy -k lvname 2 physical volume

 1. edit /etc/swapspace deleting entry for the swap to be removed
 2. Reboot the box using, for example shutdown -r now
 3. Delete swap defintion using rmps lvname