VB Exe editing

I have written a very small VB app to convert XML into a flat file format to specifications given by a customer. It has recently been noticed that there is an error in one of the field in the flat file - a date field is being produced in DD/MM/DD instead of DD/MM/YY. On going back to the laptop the code was developed on I discovered that the hard-drive was dead and I have no other copy of the source. I need someone to dissassemble the existing exe and alter the creation of the date field. I have looked myself for disassemblers and debuggers without much luck. Can anyone help? ## Deliverables 1 fixed exe ## Platform Windows 98/NT