IME, getting the tube off the XL cartos (especially DCT cartos) is easiest. I haven't repaired one "successfully" yet, meaning "good as new". Rewrapping the filler around your assembly is a pain. My is getting it consistent: if you wrap the filler too tightly, you get no draw (no airflow) and no capillary action (it don't suck liquid up like it should); if you wrap it too lightly, you can't get the tube back down over everything. I'm going to mess around with stainless steel to see if I can make it workable. I should think that would be easier.