Guide worked very well for me on the Watch4 (not classic). My battery adhesive came off during the replacement, so it was good to have gotten the adhesive card just in case.

My only note is that the Y000 Tri-point was tool small for the 2nd step. I used the Y00 Tri-point and it worked perfectly. The battery did take some effort to get out. I also used the flat edge of the plastic spudger to help lever up the corner to slide the pick in better.