With no lathe
You can file the tip down fairly flat and then get a Tweeten Facing Rotating tool, this has the shaft grabbing jig and the rotating flat disc with the 80 or 60 grit sandpaper. File it dwn until you have the dome gone and then you can use the tweeten tool which costs like, $20 to $30 to get the phenolic ferrule flat and true.
Then you can epoxy or Ca the tip and ferrule and trim to your liking.
Of course it is easier with a lathe but you can do it the way I described and then you will have the tool to do your own tips as well. Of course it takes more time and to get it perfect will take time and effort but it is possible,
hope this helps
respectfully
mike 'acedonkeyace' kennedy