Pretty sure you can't, and I have good reason to think that (Destiny)

by Xenos , Shores of Time, Sunday, May 17, 2015, 04:42 (3723 days ago) @ Speedracer513

Go to any House of Wolves weapon in the database, let's say... 55A-allFATE for example. You'll notice 2 things: 1. it has the reforge option listed among it's perks and 2. All the perks are listed as being one of a set of options.

Now, go look at say Aegis of the Kell, you'll notice that: 1. there is no reforge option listed and 2. The only perks that are shown as being one of a set of options is the last one, which are all anti-Fallen specific perks. Sadly this seems to suggest that they can't be reforged. I wish (hope?) they could be, not so much for the first few perks, but for the Fallen specific ones.