If you want to bring the wire up to the attic tie something to a string and lower it through the hole from above.
Wire feed to attic.
Remove 3 4 inches of insulation from the individual wires.
Once the string reaches the bottom go down to the lower opening and tie the cable and string together.
A decent stud finder is a must have for every wire fishing job but don t throw it back in your pouch after you ve located the studs.
Remove the covers from the lbs and push a fish tape through the conduit.
Use your stud finder to check the whole wall cavity for obstacles like blocking and abandoned headers.
Loop the wires through the fish tape and wrap them with electrical tape.
Step 8 locate the wires at the sites where you fed them to from the attic and complete your connections first then secure or conceal the rest of the wire.
You don t want to find out the hard way that you should have fished your wire one stud cavity to the left or right.
It may take some finessing as the tip of the fish tape blade passes through the drilled hole in the wall plate.
Drop a string from above instead.
To give more detail the current load center is flush mounted in the wall and my wire will be running up through the wall and the top plate into the attic.
From there it will be ran across the ceiling joists with wood braces on each side to protect the wire s.
To make the connections in the junction box hold the stripped ends of the wires side by side and screw on a wire nut.
From the attic or basement pull steadily on the fish tape while a helper feeds the cable into the wall opening.
Tie the wire to fish tape.
Once you are running the wire feed both ends of the wire through their corresponding holes and climb down from the attic.
Also wrap the hook on the fish tape so it can t snag.
Use stranded wire not solid wire.
Then it will drop down through the top plate and into the wall space to the flush mounted sub panel.
There should be no excess wire or ends left in the attic.