Well, you can just copy any project folders (hopefully audio-per project so audio folders live within project folders), and also loceate and copy any downloaded install files and serial numbers of any third-party plugins and such.
If you created any custom drum kits, effects presets, or synth presets, you will need to locate and copy those, as well.
If your Sonar installation files were downloaded files, then copy those over as well.
After you review and copy any needed folders and files to some transfer medium, such as an external hard drive, uninstall Sonar and whatever other software you are going to be transferring over, then load all of the copied data onto your new machine, followed by installing everything.
Your Sonar license is good for use on 1 computer at a time, so there should be no issue, and the process of copy/uninstall/load/install is pretty straight forward.
Bob Bone