During reassembly:

If the adhesive strips are still sticky, you can reuse them.

If you're applying new adhesive:

Use the flat end of a spudger and your fingers to scrape up and remove the old adhesive strips.

Use isopropyl alcohol and a microfiber cloth to remove the old adhesive residue.

If you don't have replacement adhesive, you can use strips of thin, double-sided tape 2–3 mm wide.

Apply the new adhesive strips to the bottom cover and remove their liners.

Firmly press the bottom cover screw pad into its recess to secure it.