If you've got a '58 and up Duo-Glide or an Electra-Glide up to '81 (I think) here's how you install one of HD's center stands. It's a pretty easy install and I've documented it on my blog in case anyone is interested. I also have a copy of the original instructions from HD.

My center stand was used, so the first part shows how to get it ready for install.

Duo-Glide Center Stand Install Part 1: Prepping the Center Stand

If you have a NOS stand, you can skip to Part 2.

Duo-Glide Center Stand Install Part 2: Mounting the Center Stand to the Frame