As has been explained to you ad nauseum, he doesn't have to push Putin out. History is full of examples where a small power that lacked the guns, dudes, and money to militarily force out a larger power were still able to win their military objectives merely by making it sufficiently painful for the large power to remain. Which is why Russia didn't win in Afghanistan, the U.S. didn't win in Vietnam (or Afghanistan), and why Iraq isn't a liberal western democracy allied with NATO.

Yeah, he doesn't get it. Asymmetrical warfare is a little more convoluted than -say- the invasion of Normandy. You would think Ukraine (or Vietnam, or Iraq, etc) would be overwhelmed quickly. Heck, look at the British and the American colonies. No way (on paper) we had a chance against the premier superpower on the planet at that time. But we made them give up and go home.**

Ukraine is also introducing new tactics with cheap technologies, specifically drones. A few thousand dollars worth of drones did hundreds of millions of dollars damage to Russia's bomber and tanker fleet, and severely damaged their air force (I'd have to do some digging, but as I recall they eliminated about 1/3 of the Russian bomber wings). Not to mention the decimation of the Russia's Black Sea Fleet (against a power that doesn't have a navy).

Continued support commitments from the west will ensure that Putin will not prevail.

**Though they did remind us that they were still a superpower in 1812, when we couldn't stop them from burning the White House, and doing whatever else they felt like.