early 99 stroker

I'm a little nervous about opening up my idm to do the 140v mod. What is the easiest way to get to the idm? I've heard that it is located under the drivers side inner fender. Is this really such a simple mod? I'm very mechanically inclined and do almost all of the work on my truck. I just don't want to mess that idm up because I know it cost a lot to replace.