Dipstick tube is just' push-on' fit, expect more of it to break off when removing what is left! Try covering the exposed hole if possible to stop any further remnants of orange plastic falling down the tube and into the sump. Maybe wrap some gaffer tape on the broken tube before yanking it of to keep all the bits together?. Soften the new dipstick tube in hot water before fitting, it should 'click' into place.
I had a similar problem when I was changing my thermostat, broke the dipstick tube (luckily I had read up so expected it to happen and had ordered a new dipstick tube too). A few weeks later, I took the sump off to check the oil strainer before changing the oil and found quite a few bits of orange plastic lodged in the oil pick-up gauze.... cleaned it all out using compressed air.
HTH,