Hi Ali,
I'm taking a look at your data, and the points are projected (looks like UTM, but they're definitely not Lat/Long). Do you know the original projection in order to reproject them to WGS84?
Other than that, the step by step is:
1) Set dataframe projection to match your source data (Projection/ITRF2005 datum)
2) Add your XY data to the map
3) Export as a new feature class or shapefile
4) Run 'Project (Data Management)' tool to project your shapefile/feature class to your new projection and save it.
5) Create new XY fields containing the new coordinates of your new projected feature class/shapefile
6) If you require it, export them to a new excel table.
Thanks,
Todd