Probably easiest to just take it to a LBS that you have good experience with and ask them to do the overhaul and ask them to please replace the bearings with new loose bearings at the same time. If the store allows such, you might ask if you can observe the overall...

Agree with other posters that, like a great majority of bikes, there is a good chance that the bottom end has never seen fresh grease... so just get it done for your own peace of mind and don't put it off till later.