変化 vs 変更

Both 変化へんか and 変更へんこう are “change” in English and they both can be used as a noun or as a verb with する ending.

The caption sentence, 時代じだいの変化へんかに伴ともなって、法律ほうりつも変更へんこうされた。means:

“As times change, laws have also been changed.”

Times change regardless of what you do or what you wish, but laws cannot be changed unless somebody tries to change them. So 変化へんか is a change which happens regardless of my/your intention and 変更へんこう is a change which somebody has to initiate or execute.

When they are used as a verb, 変化へんかする can be substituted with an intransitive verb 変かわる and 変更へんこうする (active) can be substituted with a transitive verb 変かえる, although 変更へんこうされる (passive) can also be substituted with 変かわる.

Hope this helps!