surface mounted electrical wires into stud bay--proper way?

[Cdshakes]

I have a '50s Cape--electrical panel is on outside wall of attached garage.  The garage must've been an add on at some point.  
All the wires that go to the main house run across the rafters in the garage, then towards the back of the house on the surface of the plywood garage wall.  They then go into a stud bay just above the top plate, and go down into the basement to where ever the outlets are.  
After doing some work in the garage, i want to move those wires down lower on the plywood wall.  What is the proper way to take wires that are mounted on the surface and then go into a stud bay?  Right now there's just a piece of the plywood missing and they go in there... is this ok?

Colin

[JTTHECLOCKMAN]

How about a photo or two???

[Cdshakes]

Pic from when i had it rewired-- you can see the wires in those plastic hangers on the wall... then they go into the stud bay, thru the top plate and then down thru the bottom plate into the basement.  Currently the opening is covered back up (along with the stud bay too)
I want to bring those wires down lower on the wall, so i'd be entering the stud bay cavity below the top plate.

[Foggy]

Why? How much lower?

[Cdshakes]

Why? How much lower?

just below the top plates.

I built a storage loft that sits just above the top plates-- so now that side to side rafter is gone, and the wires are just laying on the floor of the loft, bundled together.  I don't want them to get damaged up there, so i would like to re-run each one below the loft.  The wire will enter that same stud bay cavity, but it will be below the top plate--not sure what the proper way to enter it is... simplest thought is just a slot cut into the wall, and as soon as it enters, it's stapled to the side of the stud.  Just don't wanna hear this some major violation later.

Colin

[Phil Thien]

Disconnect the wire, pull it back, run it through the new route you'd like, reconnect.

Be careful w/ the wire so as not to damage it during the exercise.

I'm assuming (can't really tell from the description or photos) that the wires won't need to be any longer, maybe shorter if anything.

Don't forget the mark each wire so you know where it goes. Lots of pictures doesn't hurt, either.

[Cdshakes]

lowering it will help for length-- i'm worried about it not being long enough to go under the loft and make it over, so i figure if i lower it down on the wall, it'll give me some space.  

Don't think i'll be able to do it all in one day-- probably a few runs at a time.

[Phil Thien]

No rush when you're doing it yourself.

Just start with one, it will tell you everything you need to know about doing the others.