The hose isn't really glued on.
They get very difficult to remove after thousands of heating and cooling cycles.
You can use a razor knife to cut a slit lengthwise from the end where the clamp was and peel it off the nipple, or you can cut it through just beyond the nipple. Either way you are going to need a new hose.
If you are very careful, you can take a small screwdriver and work it between the hose and nipple and move the screwdriver from side to side until you break the seal then remove the hose. This method will save the hose, but requires a lot of patience. I prefer to replace hoses whenever possible. They are subject to ozone decay and if it is that difficult to remove it probably has little, if any, life left.
As for the sensor, you should be able to find a connector to separate. The sensor in your picture that was left connected is the ECT (engine coolant temperature) There is a small catch on the black plastic connector that must be released (by pushing, usually with another small screwdriver) to remove the wiring from the sensor. If the problem sensor really is th O2 then you have to follow the wire to the top and pull its connector apart. The O2 has a small round connector (if yours is older than 1996) and pulls straight apart. You might have to use a little persuasion.
Have Fun,
Schultz