There are some program helping you to change files from sg2 to sgy. And some examples are presented.
Firstly, there are two types of files. The first one is .exe which can help you change files from sg2 to sgy by typing
./seg2segy filename.sg2 1
Or your sg2 files may not be suitable for this program. Then you can use the second program named 'seg2fix' to fix your sg2 files by typing
./seg2fix filename.sg2
Secondly, there are four example data which are detected by me. Maybe you can use this files to complete your homework such as Using CWPSU To Plot a Refraction curve. That's all. Thanks!