Cordless for me as well. Clutch simply refers to that thing you twist on top to adjust speed. Here's what I did:
Make sure you're not drilling tempered!! Most important thing lol. If you are not sure at all about this let me know, and/or do some searching on RC and you'll find out all about it. Assuming it's not tempered, you can drill. I followed the instructions from glass-holes.com and everything was very easy. It came with a template which was helpful. I laid the tank on it's side, and had a cup of water, my drill, the template and the holesaws (bits). I laid a towel inside the tank directly where the glass that I drilled out would fall through. Decided exactly where I wanted it (make sure you are at least as far away from any edge as the diameter of your hole), then put the template there. Then I clamped it on there with a spring clamp (NOT the twisting type of wood clamp, just a simple plastic spring clamp. again if you're not sure about this just ask! The wrong type of clamp could obviously break glass pretty easily). I poured some water from the cup into the hole inside the template and started drilling- very slowly on a low speed. After a little bit once I could tell a "groove" was started I removed the template. Just keep pouring water every so often and slowly grind away. Grind is the key here. It's a sloooowwwww grind, not a fast drilling! Every once in a while I pulled out of the hole and sort of "rinsed" it out with new water and then did some more slow grinding. Eventually you will get all the way through and that's all there is to it.
Hope this makes sense, I typed it kind of fast. Like I said, if you ordered from glass-holes you will get really good instructions, or if you ordered from somewhere else you can still use the instructions from that site. It's not too bad if you just really take your time, after you get through one hole you relax a lot
Let me know if you have any questions on anything I said...
