I assume (and I only assume) that the most difficult part of @mniron install is writing instructions that would work on every sling and be clear enough for the DIYer to install it. After all .... you are drilling big holes in your fenders!
He is meticulous when he installs and we all know that our machines are not all exactly the same. Whatever he will charge to install would be well worth the money as I would have to have at least two shots of Jack before I would even attempt it!