The best Ukraine should do is to accept Russian peace offer.
Demilitarize ( I don't think much of the big ticket systems are left anyway in terms of weapons/equipment or dedicated military infrastructure).
Sign a pact to not join NATO and be a neutral state.
Zelensky can stay as Russians didn't ask for his resignation.
There is no point to this war, will only lead to more destruction of infrastructure and loss of lives in Ukraine. Literally at this point they are fighting for the west rather than their own benefit.
In return ask Russia to roll back recognition of the newly independent republics (if they are given some form of autonomy within Ukraine) , preserving Ukraine territorial integrity.
( West sees Ukraine as Afghanistan, they don't care at this point what happens to Ukraine. They are only interested to further agitate the conflict to bleed Russia. Its clear what they plan to do and Ukraine interests is the least of their concern right now).