I've been looking all over the web for help on this, but was unable to find a video matched the 2015 Sportster 72's setup. It seems like the reflectors are attached to the underside of the rear fender, and in a tight enough spot that prevents removing the nuts. This consequently prevents there being enough space to slide the side plates into place and attach them. I would take it to the HD dealer..but they want $220 to install them..

Any advice on this would be greatly appreciated. I spent about 3 hours today working on this until it got dark and I had to pack it in.

 

Post pictures of what you're talking about.

 

So the reflector is attached to a plastic housing that connects to the underside of the fender (unlike other Sportys I've see where it's simply attached to the outside). The plastic housing seems to sheath the nut that holds on the right rear turn signal, and it's blocked from being turned.

 

I just realized it looks like there's a wiring harness for the tail lights that's part of the side reflectors. This is probably too big a task for me to do on my own. Gonna bite the bullet and take it to the dealer on this one.

 

If you're having trouble getting a wrench or socket on the nut try jacking up the bike so the rear tire drops down a little more. You may have to remove the shocks in order to get it to drop even more.

 

I ended up taking it to a guy nearby I found on Craigslist for $100. He was familiar with the '14 and '15 Sportys..said they changed the tire base and made it wider. That made it more difficult to do the install without pulling the shocks off. Either way, issue resolved.

 

I'm having the same problem! My concern is now that I've successfully removed the rear strut bolts I loosened the front bolts but only enough so that the nut keeps spinning. So now I can't tighten it enough to ride to a dealer/shop for a proper install. Can I safely ride the bike with the front strut bolts that are loose?