Get a small container of hot water and dip the ends in. That should be enough to soften the ends.
If not, you might try a tiny dab of silicone grease on the barb, but make sure it has no petroleum content. Spread the grease along the barb, avoiding the open end. If you are unsure about the formulation of the grease, avoid using it. You should also get the ends of the hoses warm or hot even if you use the lubricant.
You should clamp the hoses on the barbs with the proper hose clamps. These are not the worm screw type automotive hose clamps, but clamps that do not have the worm screw.
They look like this:
(see first attached image)
http://www.tooldex.com/western-enter...ps-119993.html
You can search for them by the part numbers WE-501, WE-502, 312-501, or 313-502. I would guess they are commonly found in weld shops.
You can also use Oitiker clamps, which look like this:
(see second and third attached images - two styles)
http://www.amazon.com/gp/product/B00...X569HMKAKST2M1
You can also use crimped ferrules.
(see fourth attached image)
http://westernenterprises.com/wp-con...e-Ferrules.pdf
Having said that, most people use automotive clamps because they are inexpensive and readily available. However, they are not recommended. (If you want, I can link articles, but don't have the reference readily available.) When you tighten these worm screw clamps, the rubber of the hose extrudes through the band, which can cause the worm screw to disengage from the band.
Connect hoses
