Hi @rpaulorodio & welcome to the KNIME forum
This can be easily done using a -Column Rename (Regex)- node:
Please be aware that column names must be unique and therefore this is only valid if you have ONLY one column named “Column (something)”. For instance, this solution would not be valid if you have two columns named “Column (#1)” and “Column (#2)”.
Hope it helps.
Best
Ael