How do I eliminate scale from a bay tree?

Get down to the Garden Centre and ask them what they would recommend you use.....

Best way is to dip cotton swab in rubbing alcohol and dab each & everyone of them removing it as you swab them this kills and removes. Make sure you put everything in plastic garbage bag and tie it shut. If infestation? is really bad it may need thrown out(sorry) unless you want to do this painstaking treatment & depending on size of plant.How bad you want to save your plant. Better check other plants if you have them together in one area. Some say overall treatment with pesticides but you'll have to douse each and every little nook & cranny,on top & under every leaf to get them all.If you are using it for cooking it'll be useless after pesticide treatment.

Neem oil or Azamax for light infestations. Ladybugs are a natural approach but not for heavy infestations.

Hello—if its scale you may want to treat the critters.

https://www.tree-land.com/sugar-and-sap/kill-bark-scale-crape-myrtles/

https://pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/2808/2808-1012/2808-1012_pdf.pdf

Please also remember to utilize your local cooperative extension office for any gardening, garden pest ID and weed Id and remediation problems. These offices are manned by volunteer master gardeners on site there waiting to answer the communities questions that know your local situation quite well.

Master gardeners are required to volunteer back designated hours ( plus continuing education) each year to maintain MG certification -this community outreach and education is their goal. If the MG cant answer your question on the spot—-they often send out specimens to the local universities my office utilizes Virginia Tech for plant, insect, or disease identification.