You already have Firefox Quantum (57), so you don't have to do anything.

If you have Quantum then Mozilla has totally f**ked up your bookmarks and all other setting and ad-o-ns. REALLY, REALLY lousy product you cannot get rid of. I suggest going with Chrome! Mozilla, I hope you have a s***ty holiday season! You've ruined mine with this lousy Quantum upgrade!

....the hangs I get with Quantum is beyond belief. I've tried all what is obvious to no effect, just wasting debug time. The help site is basically utter toss, same with windows. Back to windows 7 and earlier FF.

So sorry for switching to Firefox Quantum ... I lost everything with Quantum that I had with an earlier Firefox Version ... Quicker speed means Nothing if it does not do what you have previously done with add-ins and other things. ... I guess I'll switch to some other browser that can help.