Let your snake slide through a damp towel and see if the skin comes off with minimal pressure.
Alternatively you can give your snake a bath, with warm water at 27c (use a digi therm to measure) for 10-15 mins and then try with the towel to remove the shed. This should do it.
If it has been there for a while there is a chance the blood flow to your snakes tail has been compromised, and it may be damaged. If this is the case, line the viv or faun with kitchen towel and keep the area, including the water bowl, scrupulously clean to prevent infection. Tamodine is a good antiseptic for reps.
In future make sure you check your snake immediately after a shed for both retained tail tip and the eyecaps.
Good luck!
9.11 Cornsnakes 1.1 Hogg island boas 1.0 Dwarf Burmese python
provide a damp hide for a few days and then bath him is what i'd recommend
if it stays there it could cause the tip of his tail to die and drop off, i'm sure you'll find a few threads on that too if you search for 'necrotic' !!
cornsnakes, ratsnakes, bullsnakes, boas and day geckos