I did a quick web search and didn't get anything specifically for the mustang but here's a couple I found for others. Should be similar, other than getting the trim pieces off - remove old top, clean metal, start at center and work out basically;
http://www.legendaryautointeriors.co...ON%20GUIDE.pdf Archive / File /vtop.htm
Do a search, you may find more, check with the usual vendors, NPD / Mustangs Unlimited, etc., they may have instructions that come with the replacement tops.
Or you could get a quote from a shop that does convertables if you're afraid you may not be gifted enough, I imagine it'd be easy to end up with wrinkles or crooked if you don't have 2 people to work it.
Jon
1968 ford mustang 
