How to remove paint from cement walkway?

Power wash and scrape.

Maggie...here is a link showing a couple of different ways..

https://m.wikihow.com/Remove-Paint-from-Concrete

Don't mean to be flip about it but have you thought to add more spots in a design or some sort?

Maggy, Hello. Try some turpintine, or paint remover, or check Home Depot or Lowe's for that. Maybe linseed oil. The paint department will help you with that, call them first, you might have something at home you can use. Aloha!

I would start with pressure wash then a solvent and another power wash. If you have to scrape, get a floor scrape to save your back.