350L 4×4 input shaft bearing

I picked up a pretty 93 350L for cheap recently that had "transmission issues". I started pulling things apart and believe I found the culprit of the issues. It looks like the input shaft bearing cage blew and the bearings were just sitting in the hole, allowing the shaft to wobble any time the bike moved. Do I need to pull the whole transmission to press the old out/new in, or can it be done in place? I'm fairly mechnically inclined but all my work has been on motorcycles and this is my first time with ATVs. Any advice or help is greatly appreciated.

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Which piston

I am wondering what piston will last long on a 1989 polaris trail boss 250 2 stroke. Had purchased a Namura top end rebuild kit on amazon but it didn't last a month. ANY feedback appreciated