What is the best way to remove old glue from concrete floor?

https://www.doityourself.com/stry/how-to-remove-adhesive-from-a-concrete-floor

If you google this, you’ll find lots of opinions. Two I found interesting were 1) laying newspaper over a small area and ironing, then quickly scraping up the melted glue.

The second suggestion was hydrogen peroxide, leaving it sit for a bit, then scraping. Were I to do that, I think I’d go over the area first with an old iron rake or wire brush to make the glue surface more permeable. Not too hard, as you don’t want to scratch the floor.

Many suggestion involve large quantities of glue removers, including leaving some soaking overnight.

I would use a heat gun and a metal putty knife I think that would work pretty well and go pretty fast.