How to reset password when I can't run install disk

I have an old PowerBook G4 that I've kept to eventually get all the data off the hard drive and then recycle it.

However, back in 2011 my charger stopped working and Apple stopped making them years prior (I looked and there are no more aftermarket chargers available). I just found it again in the garage and want to finally get rid of it but need to get the data off first and then wipe it.

So here's my problem, I can't even begin to remember what my password was on it, been 4 years since it worked and I got a new Mac to replace it. I do have the install disk but the Power Book won't be able to turn on to actually put it in the drive and run it. I was considering getting an enclosure and possibly use the hard drive as an external but without the password will I even be able to use it?

So, my main question is, when I set a password on OS X (This would likely have been 10.5, Leopard, I don't think I was able to upgrade to Snow Leopard) does it also lock access to the hard drive with the same password? I DID NOT encrypt my hard drive, just the standard OS X login password. If I take the drive out and try to plug it into my current computer will I have to have that password? If so, how do I get around it? Can I plug it into another computer and then run the install disk in that computer to recover it that way?

What other options do I have? I called a few repair shops who say they could brute force through the password and get the data off but I don't have $100 - $150 to spend on some info that is probably not worth it.

Thank you for your time