Hello David,
Firstly backup your system since SFW5 changes cannot be undone.
Then open the client settings for changing in SCC4.
Then;
Change System Change Options to Modifiable also.
To do this,
Run SE03
Goto Administration --> Set System Change Option
Set Global Settings to Modifiable.
You can use Edit Menu items to change settings of Software Components and Namespaces also to modifiable and not modifiable.
Then run SFW5.
Hope this helps.
Regards,
Yuksel AKCINAR