take a look at the picture in the link. should help you out a little.
http://www.slingsonly.com/mp5_tactical_sling.shtml
also found a little bit on an instructional when I clicked the 2nd link google spit out:
http://www.hellasairsoft.com/article...all/index.html
here's more from google:
3 point sling on mp5 - Google Search