I recently had to send in one of my LT4's for the very same thing. And yes, as others have already said, the whole tip will need to be replaced. As far as I understand, the entire tip is pressfit onto the pole and does have to be knocked off the end. This can be done at home, however, if the carbon fiber shaft breaks...well, at least they do sell the upper or lower shafts only on the GG site...
Also, I know that turn around time depends on how busy they are at the given time, but when I sent mine back I had them back 6 days later. I shipped it USPS Priority on a Monday afternoon and it was back to me that next Saturday afternoon.
Also, they are using different tips that what they were using, so if it matters to you about having matching tips, I would ask them about sending in both to be changed out.
Here is a little write up I put on my blog about it: