Front axle clicking.

Hey recently I noticed a distinct clicking sound on my 2019 Toyota Prius (128k, FWD) specifically when coming to a stop, I know it’s the axle because I did the shifting to neutral and the sound went away. Now this just started and it’s very faint but I’m assuming it’ll become a big problem. I drive my car a lot, I got it last September at 95k miles so I try to patch up anything before it has a chance to develop into something bigger. So,

How urgent is this?
Is just a regrease ok?
How hard is it to replace an axle DIY?

I do my oil and transmission changes, but coolant, break I seek out a mechanic mostly because I don’t have the craziest setup at home, plus it’s relatively a very infrequent maintenance for this car.