Cannot erase drive of Power iMac G5

I have a 2005 Power iMac G5. I want to completely erase any information before sending it to the recycling/trash bin. I have read and tried many of the articles that appear in this forum. Thus far, I have had no luck. I own the three OS X discs that came with the computer. I have:

1) Opened disk utility, and tried to erase the hardrive from there. Nothing.

2) I tried to use the installer CD 1 as the start up disc, but the computer just freezes on the apple icon when it boots (though, interestingly, after a few seconds, without the twirling thing underneath BTW, a few small lines appear to the left of the apple, pushing the apple a little to the right.)

3) I tried to restart the computer with the CD in, and then hold the C key (or the Command R key, or the...I have tried many things...) I always get the frozen screen on the apple icon.

I do not know what else to do, other than to open the computer, take apart the motherboard, and break it into pieces. It is the non-tech way of doing things (the cavewoman-way, I guess.)

If anyone has any clue as to what is happening and what it is that I can do to erase the computer, I'll much appreciate your assistance.

(Note: In order to post I had to choose a "community" of either Mavericks or Lions, no Snow Leopards, and much less of Dinosaurs, which would be a much better fit to the Panther OS X. So, sorry if this posting goes to the wrong people. I hope someone will be able to answer my plea. Thanks in advance.)