It used to be the case that you could replace the inserts on Odyssey putters relatively easily, even as a DIY job. However, now that the technology has evolved with the introduction of the Ai insert, this is no longer possible.
Should you encounter an issue with your putter’s performance (which is highly unlikely, given the impressive craftsmanship on display) you should contact Odyssey customer service, who’ll advise you on the best course of action.
It's also important to note that the inserts can differ, depending on the specific club. For instance, most 'standard' Ai-ONE putters feature the Ai-ONE urethane insert, whereas the Odyssey Ai-ONE milled putters feature an insert made from a single piece of titanium. So it could be wise to try different variations before you buy!