Update:
I did manage to get the parts open in an editor, and I have them working with the LDraw system. Now, my only problem is that the origins of the parts are not well placed. I'm not sure exactly how to fix it; I've googled the problem in several ways but to no avail. No tutorials seem to specify "how" to set an origin... perhaps you can't set an origin! I don't know. If anyone does know, please respond.
I did manage to get the parts open in an editor, and I have them working with the LDraw system. Now, my only problem is that the origins of the parts are not well placed. I'm not sure exactly how to fix it; I've googled the problem in several ways but to no avail. No tutorials seem to specify "how" to set an origin... perhaps you can't set an origin! I don't know. If anyone does know, please respond.