Mounting the router to the sled

Hello all.
I finally got the Ridgid router to go with my makermade maslow and pre-cut sled.

The question I have is how to go about mounting the router to the sled. And what’s the process?

I know that I want to get the axis of the router as close to the center as possible.
I have a friend printing me one of those alignment jigs.
but then what? How do I know it’s centered?
And how exactly do I screw it down? The makermade pre-cut sled has some scribe marks on the top, but no holes to screw through from the bottom into the base of the router.

As far as I can tell it seems like I need to set the router into the jig and mark on the top where the mounting holes need to be. THEN, lift it all off, drill holes from the top, then run the screws in from the bottom into the router in the jig?

Is that what people do?
Thanks,

KM

That is pretty much what I did and it works.

yes you will need to buy three 1.5" long 10-32" screws from hardware store as well
they are not included in kit. you can also draw the sled and print it out on two sheets of paper for alignment