If you take the collet out along with the nut (really should so you can clear any sawdust out of the vanes/slots of the collet which will keep it from tightening securely), then hold the nut between your thumb & forefinger while your fingers curl around the bit. Then screw the nut onto the shaft with your thumb & forefinger while pushing the shaft lock button in with your other hand.
Snug it with your thumb & forefinger. Then adjust the bit up or down until there is about 1/16 or 1/8" between the collet and the end of the flutes. That will keep the sawdust & chips from riding up the flutes into the collet.
Then take your wrenches and tighten the nuts. I tighten mine more than I would with an ER16 or 20 collet because of the way the Makita collet is made. But remember you will have to loosen them some time soon 