I picked up a gorgeous D2 off of eBay a few months ago and had to align it. The easiest thing I found I could do is to buy a Beseler "lens align" kit from Calumet or any other Beseler dealer and then mount that on the bottom of the cone. A trip to the hardware store, some super glue, a couple of screws, and it was mounted tight and for life.

With the lens then mounted on to that Beseler board, you can easily check and adjust your alignment at any time and fit it fast by adjusting the three allen-wrench screws. Now, whenever I need to print, first thing I do is check the alignment with a grain magnifier on the first neg and after about 30 seconds of checking and making a tiny adjustment here and there, I'm good to go!