Any tips on removing the roller on some pheromone products? Want to use a bulb dropper instead. Or do I request it during checkout?

I think your best bet it's to request a bulb dropper option if available

Penknife blade works pretty well for me. carefully work round the edge of the roller, lifting just a little at a time.

You might want to set the bottle base in a lump of blu-tac or similar sticky substance to help avoid spills when you pop the roller.

Don't try using a mole wrench like I once did - messy!

The white plastic edge holding the roller in one of my bottles cracked and the ball came right off. I'd suggesting removing that if you want to open the bottle.