We use a puller to pull the gear off the crankshaft...
...and remove it. You can remove the gear from the crankshaft on the engine too.
(Information copied from the portal: VazBook)
Using a screwdriver, pry up and remove the segment key from the groove.
We punch it with a punch and, having hooked it with a hook, we take out the plugs of the crankshaft oil channels. We clean the oil channels.
We wash the crankshaft in kerosene or diesel fuel, blow out its internal cavities with compressed air. We press in new plugs and calk each one at three points with a center punch.
We install the removed key and gear using a brass hammer.