Sorry I didn't see this sooner. Yes, you can remove the cover with the cable; just be sure to pull the cover straight back so you don't damage the shift fork. It'll be a nice challenge getting the cover back on without smearing all of your RTV.
But...you're certain you don't have a drain plug? Because I've got drain plugs in both my D30 and my D44 OX covers; I just changed fluids over the weekend so I'm familiar. Both are recessed and only noticeable if you look up. They are Allen head.
Dude...I would double-check on the drain plug situation. OX specifically designed the covers so you DON'T have to remove them for gear oil changes. Now you'll likely have to readjust your cables...
2001 2.5L TJ, HPD30/D44 with dual OX and 4.88, full armor, X20-8 winch, 35" STTs on 15x8 black Cragar Soft 8s, 1" BL, 1" Brown Dog MM, 4.5" suspension w/ fully adjustable control arms and tie rod upgrade, OBA