I recall there's a DIY for that on Pelican parts forum somewhere. Fortunately, my car came with the 18-button OBC. So, I didn't need to do it. I don't know for sure if it's a complicated task or something easy. May be someone else can help you better
best regards, Tony Sticks [url=http://www.bmwe36blog.com/]BMW E36 Blog[/url] / [url=http://www.bmwe36blog.com/forum/]BMW E36 Forum[/url]
I installed a ScanGuage tool in my 1996 328is that does everything an OBC does and more. I find it much easier to use and it is a direct plug and play. Also has the benefits of being a scan tool for reading OBD codes. Cost about $200 shipped.