Well you are not going to like my suggestion but I sure others with follow and disagree and tell you they did it with a Dremel and a paper clip so you'll have some options. My opinion is to forget any type of conversion and just purchase a .38 Super 1911 instead. The reasoning is you'll have to purchase a new top end (slide (breach face is different) barrel and bushing (have them fitted), extractor, slide stop, and recoil spring), and .38S magazines and then as important have to have the feed ramp on the frame built up and then machined for the .38S (a .45 ACP feed ramp will not work.) You could purchase a ramped barrel and have your frame machined to accept it but................. The work involved and expense really don't justify the conversion unless you were skilled enough to do it yourself and even then you would have your hands full.