You have to do it with your thumb.

Yep. Level winds bind up under the pressure of a very large fish, that's why big game reels don't have them.

Yup, it's called having an "educated thumb". You don't have to focus on laying the line down exactly even the way a levelwind does, just use your thumb to guide the line to the part of the spool you need it on. It'll come naturally to you very quick.

Big reels don't have a level wind as a safety issue. I seen one guy get his finger broke when it wandered in there as a shark was starting it's run. With heavier line you don't need to thumb it as much. Sometimes rolling the rod left or right will do it too.

Joe

The line will naturally want to move to the center of the spool on it's own. If you didn't thumb it the line would spool up dead center.

What you really have to do is gradually push the line to the right as you reel up. Once the line reaches the far right you release it and continue to reel. The line will gradually migrate back to center on it's own. Once center you guide it to the left this time. Then you repeat. It takes a little conscious effort at first and then becomes second nature. You won't even thing about it, much less remember actually doing it.