Yes, sure, if the parens should be removed only on the sixth (or actually seventh) field, with the field separator deemed to be one space (or possibly several consecutive spaces), and not thereafter, then we have to split on white space and make the substitution on the field (seventh) which needs to be changed. This requirement was not in the OP (to which I was really answering) and was added at a later point.

The problem is still that the data seems to be almost free format (or at least with a very poorly defined format), I would also not be surprised if we discover new requirements.