You can’t. It’s an uncomfortable reality but one that we have to likely confront if the lines haven’t dramatically changed by the winter which is possible given Russian ineptitude. Assuming both sides spend the next 5-6 months largely going nowhere then realistically the only way Russia will unilaterally change its position is through an invading army marching in to Moscow, revolution, or the hope that another Gorbachev type figure arrives. No one is invading Russia and no signs of either of the other two so we are left with two probable outcomes.
The first is the war in Ukraine continues until Putin dies (and even then we don’t know if his replacement will want the same), this requires the west to keep supporting Ukraine both directly and also with the indirect consequences (energy and food prices) because we know the Russians are now dug in and can (and will) indefinitely send men to their death and not give a flying fuck.
The second is some sort of peace agreement is reached, for this to happen Russia needs to make overtures for peace (which isn’t happening now as far as we know), and here should it happen there will be uncomfortable compromises. Sadly Ukraine isn’t in any position to dictate what those compromises will be (if it were there would rightly be no compromise), the west will decide. Of course the west isn’t stupid and I suspect it will be mindful of how little Russia can be trusted so overseeing elections, putting peacekeepers on the ground or signing treaties or having ukraine join NATO are all mechanisms to get as much assurance for Ukraine as possible whilst at same time being conscious of what Russia will agree to - the further we can kick the tricky items down the line to a time Putin no longer walks this planet the more likely agreement can be reached with him.
And yes it’s all shit because on the surface the aggressor is “rewarded” for their behaviour which makes a mockery of so called world order.