This DIY needs some modification:
1. To unclip those two well hidden nasty tabs, take a long thin screwdriver or very small/thin Allen wrench and, from the bottom, shove it very firmly all the way until it stops right between the very outer case and what you can see of the tab in there. On the top of the case, you will see two small square openings..... one for each tab. The tab you are trying to push against is hidden to the side of the hole toward the outside case. You are forcing the little lock tab away from the outside case toward the middle of the opening. as you pry the tab, it will appear from the outside of the case toward the middle of the little square opening. If you don't see it, you're doing something wrong.
2. The high beam/low beam switch contacts are the three metal relay type contacts on the TOP of this assembly. All three are connected together with a plastic sleeve. Slide the contact assembly out sideways (toward you) taking care not to get the metal tabs caught on the white plastic assembly underneath. Very lightly emery the corrosion off the contact surfaces. Note, the brass contacts are very soft! Do NOT sand it too much! Apply a VERY LIGHT coating of CONDUCTIVE GREASE if you can find any to the contacts. If you use any more than a tiny amount, it will short the contacts out defeating the purpose of the switch.
3. When re-assembling the metal tabs, take special note that the black plastic holding them together slides into a channel on the switch housing. It is possible to slide them in just above this channel which would be incorrect. Look at the contacts right after sliding them in. If they are NOT making contact, you slid them in above the little channel! Take 'em out and slide them in correctly.
4. This assembly MUST have grease on the turn signal sliders or the metal-on-metal action will wear away the switch contacts. Use NON MIGRATORY (heavy) grease used on them! In other words, do not use a lubricant such as WD40 as it is so thin it will migrate away. Use a heavy grease. (which means it doesn't run) Di-electric grease can only be used sparingly as it DOES NOT CONDUCT ELECTRICITY. Use too much, and you'll insulate the contacts. Try and find conductive grease or conductive lubricant if you can, but put a THIN COAT on the slides so they don't short to each other.
I for one absolutely hate the column mounted high beam switches. I grew up driving cars that had the floor switch. Half the time I reach up to turn off my cruise as I'm coming up on someone, and I hit the high beam instead my mistake. Boy does that piss people off. You can buy the old type floor switches here: http://www.google.com/products?hl=en&q=floor high beam switch&um=1&ie=UTF-8&sa=N&tab=wf