Cut a hole for each box with a drywall saw or a saw appropriate for the wall material then feed the wires down from the attic or up from the basement toward each hole using a fish tape or a fish stick and have a helper catch them and pull them through.
How to put speaker wires in the attic.
5 go up in the attic or down in the basement and look for your coat hangers.
The staple gun should be loaded with wire staples designed for holding the size and type of wire you are running.
Thread the fish tape when you find the hole in the wall plate remove the wire then uncoil the end of an electrician s fish tape and insert it through the drilled hole in the wall plate.
Or of course you can splice cables if you feel that s easier to do.
To run cables vertically go into the attic or basement and drill holes in the wall plates above or below the locations of connection boxes.
Buy the correct gauge speaker wire for the expected power output and the required distance.
While one person holds the flashlight the other person should use a staple gun to run the wire along the rafters from one entry hole to the other.
Then continue running the rest of the cable to the second speaker.
Bring all of the wire up into the attic.
When you get to the first speaker carefully slice the outer sleeve and pull out two of the conductors.
The actual install of recessed lights here https youtu be 5yc8aqnvqqg the long bit is actually used.