The SUBSTITUTE function is case-sensitive and looks for instances of the string in the cell.
Substitute function in excel replaces any character of selected cell value with anything we want.
Syntax
=SUBSTITUTE(text, old_text, new_text, [instance])
Arguments
1. text - The text to change.
2. old_text - The text to replace.
3. new_text - The text to replace with.
4. instance - [optional] The instance to replace. If not supplied, all instances are replaced.