How do i connect/disconnect electric from drivers side sun visor?

Mounting screws are behind the prastic cover where the visor connects to the head liner. Flip this plastic cover over usually from where the rod goes in toward the center of the car with a small screwdricer then remove screws and wala.

Under the head liner

If you are adding a light from the factory, the wiring should be there all ready, you just ned to remove the "a" pillar cover to expose it. You might have to pull part of the head liner down as well.

Typically by dropping the head liner.They are large,ridged and don't bend .Most head liners are fastened anywhere you see something touching them,sun visors,grab handles,dome light housing.most of the time you should be able to do your wiring thing without completely removing liner,but if needed it could be done by dropping down at angle and sliding out through rear hatch.Be careful as they are very expensive to buy.

There is usually a cosmetic cover hiding the two phillips head screws which attach the visor to the overhead. These covers 'clip' in place and can be removed using a small flat tip screwdriver. Once removed, you can then access these two phillips head screws. Remove the screws & gently remove the visor. You will find a wire harness connector to the visor. Find the release tab on the connector & press on it to disconnect the visor from the wire harness in the overhead. Installation is reverse of removel.
Go to www.hmaservice.com and register your vehicle by VIN #.. you'll then have access to wiring diagrams, shop manuals, service bulletins, illustrations and procedures, etc.

I don't know why you would be at a dealer,
unless your car was under warrantee

Of coarse you can resolve yourself

Check the door seals

Go to a local repair shop and
borrow the air hose, to blow out the
drains on the bottom of the doors

If you have a sun roof, the drain hose may be off.
In which case you remove the sun visors and
whatever else to drop the head liner and reinstall the hose

If you have a sun roof,the drain hose may be off. If so,remove the sun visor and pull down the head liner, to get to the hose and drain fitting on the sun roof opening

2006-2007MY SONATA SUN VISOR
REPLACEMENT (SERVICE CAMPAIGN T64)
CAMPAIGN APPLIES TO VEHICLES LOCATED IN THE WESTERN,
PC, AND SOUTHERN REGIONS ONLY. THIS WOULD INCLUDE
THE STATES AL, AR, AZ, CA, CO, FL, GA, HI, KS, LA, MS, NC, NM,
NV, OK, OR, SC, TN, TX UT, AND WA.

a creative solution is to use velcro tape. a piece on the visor and a matching piece on the roof liner

remove trim at edge of liner and look above the liner ti reval a connector.