I am using SQL Server 2008 and Navicat. I need to rename a column in a table using SQL.
ALTER TABLE table_name RENAME COLUMN old_name to new_name;
Alternatively to SQL, you can do this in Microsoft SQL Server Management Studio. Here are a few quick ways using the GUI:
Slow double-click on the column. The column name will become an editable text box.
Right click on column and choose Rename from the context menu.
For example:

This way is preferable for when you need to rename multiple columns in one go.
For example:

NOTE: I know OP specifically asked for SQL solution, thought this might help others :)