Start buy using a paternoster rig with jig on it and finding the ground that holds squid, 20-35m seems to be good for KGW in numbers, large fish can be caught shallower water but they don't seem to be as common. We drift and feel the line if the jig is snagging on weed occasionally that's good, if you can feel reef snags move elsewhere or keep drifting, you'll eventually find a spot! Sounders are useful but not essential, large KGS can show up as long marks very low as they move quickly and forage on the seafloor. 

Some people like to anchor but I prefer to fish a slow drift in a pattern covering the area squid are being caught, using the fresh squid tentacles as bait I run a 20lb paternoster with small circle hooks this does a number of things, reduce bi catch of smaller fish, reduce foul hooking's and makes releasing unwanted bycatch like gurnard or grinners easier (they love swallowing the whole bait and hook) 20lb certainly isn't necessary for kgw but with a circle hook there is a very good chance of landing larger fish that might take a liking to the bait. pinkys, dhus etc. 

KGs are fairly good fighters and on light gear can be a lot of fun, but fish a light drag as hooks can be pulled especially on the first run, if its obviously not a KG then tighten your drag as appropriate. 

Also a red/orange glow bead, they seem to work.  

Things to remember- 
 

-fresh squid 

-20lb leader 

-small circle hooks 

-light drag 

-slow drift 

Good luck!