John,
Your Beocom 2 handsets can have their software updated by your dealer. To update the software they fit a service jig to the phone which connects to two gold pads and then it is connected to a PC and new software can be download. Assuming your dealer has this jig available, then it can be done in no more than 15 minutes, however if they do not have the jigs, then they will almost certainly send your phones to B&O. Cost will depend on dealer, but if they are sent to B&O the cost will be quite a bit more.