I am installing a new backplate (this is my first repair; I was CERTAIN that I would crack the back glass, and I was NOT wrong) but I’m not sure how tweezers are meant to remove gooey adhesive! I simply used the blue plastic pry tool as a scraper and gently rolled up the goo. Maybe the glue is different because I have a refurbished phone? That may also explain why I had so much trouble with Step 1. Hope that this helps!