You can change it via wlst like below but I don't think WITHOUT server restart all changes will take effect. Dynamic changes usually dont need a restart but if its an non-dynamic then yes you have to restart
cd('JDBCSystemResources/JDBC Data Source-0/JDBCResource/JDBC DataSource-0/JDBCDriverParams/JDBC Data Source-0')
Activating all your changes, this may take a while ... The edit lock associated with this edit session is released once the activation is completed.
If you get any non-dynamic ds entries password changed then you must restart the server to make this effective.