I recently replace one of our sinks with a new one. I had a number of struggles. Most could have been solved by doing one simple thing.
Put everything onto the sink before you install it.
That means putting the new faucet on and tightening it down. Connect the water supply lines (if you are adding new ones, or remove the old ones from the shut off valves and reconnect after the sink is in place). Connectthe drain and tighten it down. You could even test for water tightness by temporarily putting the sink in place and pouring a pitcher full of water into the sink, both with the drain stopper down and with it up. Connection the mechanism that lets you open and close the drain.
Trust me, all this is much easier doing it standing up at the sink counter than on your back under the sink. The only thing you will have to do is up some sealant under the rim of the sink, put it into place, connect the supplies lines, and the drain. You might have to do some adjustments to get the drain to match up, but that should be minor, and everything else would be done.