I do mine myself. Takes about 2 lazy hours. You can get some idea how it's done on older double paned windows here (this is at my RV travel and repair blog site):
Repairing Double Paned Window LeaksThese days, they're not made as mine were so it might be quite a bit different procedure for your newer windows...but perhaps the article will give you some idea where to begin or what's involved.
If you're a DIY'er you might come up with your own procedure. If you do, I'd encourage you to post pics for us.