Call and ask for what you want. As long as your request is reasonable, they should at least consider, and perhaps accommodate, your requests.

However, you will not get a free hotel from them.

If you change your ticket in such a way that it has an overnight stay where there are options available that don't require a hotel, then you must state up front that you are happy to deal with the overnight yourself - otherwise it simply won't even be looked at or offered as a viable option.

(And don't read into this the corollary, that if the only available rebooking options required an overnight that they would pay for a hotel either.)

It never hurts to ask if you want to swap from one TYO airport to another, but bear in mind that they may refuse this. (Are you sure they even serve both?)

EDIT: I just realised that you booked via an OTA. As such, you cannot call the airline (which is what I had in mind when writing the above) and you will likely find they will be far more reluctant to play around with your ticket, or to give you an overnight stop or change the destination airport