Peel away and remove all the old display adhesive from the body of your phone.

If you're reinstalling your existing display, remove all the old adhesive from that as well.

Use the point of your spudger to scour away and remove any smaller bits of adhesive that remain stuck.

Be extremely careful not to accidentally puncture the battery with your spudger.

For best results, clean the area underneath the removed adhesive with isopropyl alcohol to help prep the surface so the new adhesive bonds more strongly.