Hi, presuming the horn is still attached - just. Best to remove it totally, use hoof shears to carefully snip round as low as you can - like you would trim your nails. It may make it bleed a bit more but it will stop.
I had a ram kept ripping them off or half off and blood went everywhere but if you wash the area and regularly spray with purple spray it should stop. Watch out for flystrike. The vet or local country store may have some wound powder which will help the clotting if it persists in bleeding.
It looks worse than it is and generally the horn re-grows quite quickly.