Get the instruction book out and look for a picture of the winder in the router. There is an indent on the base where it goes through. Once I located that, then bolted the base to the plate, I used a find black marker to outline where that indent was onto the underside of the router plate. Then drilled a hole in the plate AFTER using a punch to make a small indent centered in that marked opening. The indent keeps the bit from wandering if you do it freehand, but unmounting the router and using a drill press is better if you have one.
On my Triton mounting plate, I drilled the hole slightly larger than the crank, then cleaned up the edges of the hole with a slight taper to keep the aluminum plate from scratching the height adjustment crank shaft. Much easier to do than describe. Be sure you have the switch and safety interlock in the right position so you can reach it easily before you mark and drill that hole.
The more I do, the less I accomplish.