I have shipped large UV units before. I would leave the sleeves installed in the unit. Bubble wrap the unit well. Bubble wrap the ballast as well. Take pictures of the unit before and as you are packing it just in case there is damage in shipping. You can then show that it was in good shape and well packed.
Place it in a large box that leaves 8-10" of space on all sides and pack the box with the UV unit centered in packing peanuts. Not paper as paper will compress and allow the UV unit to shift in the box. If for example the UV Filter is a single tube model that is 36", I would find a 20"x20"x48" box for it, You could go a bit shorter on the length but you want to insure that the filter is away from the sides and ends so if the box gets dropped, there is plenty of cushion between it and the sides.
Be sure to put fragile stickers on all sides and insure if for replacement value.