@Cimeaka0
Hi Newby C, Alterations to long term bookings are difficult to advise because any cancellation will be subject to your cancellation policy. That will effect how much of the guest payment you will retain!
The best advice I can give is, don't get involved with upfront discounts......not for any booking! Once a length of stay discount has been offered it is difficult to impossible to cancel should the actual length of the stay or some other circumstance change.
I do not offer up-front discounts! That is not to say I don't look after guests who book a longer term stay, but I will offer the discount in the form of a refund when the stay concludes so I can assess what discount might be appropriate.
Up-front discounts are open to abuse and Airbnb will suggest offering ridiculously high discounts of up to 45% for longer term stays which, if you adopt, will actually see you lose money rather than make it.
At the end of the stay, taking your cancellation policy into account, work out what you feel is an appropriate discount for that stay (include the guest if you like) and go to the message stream with that guest. Scroll down the booking statistics on the right of the message stream until you come to an item marked 'Send or Request Money', hit that tab then 'Send money', put in the amount you wish to send to the guest in the amount box, hit Submit, the money will automatically be sent to the guest and deducted from your next payout.
If you do this you won't get caught and being stiffed with an inappropriate discount!
Cheers.......Rob