Nothing is said about replacing the black sticker over the connector. I set it aside and found its adhesive was good enough to stay in place and put it back on during reassembly.

The gasket is black and won't look translucent blue as shown in the picture. The die cut is poor and I destroyed the first gasket I tried and bought a 2nd one. Carefully complete the die cut with an x-acto knife or equivalent before separating the gasket from the sheet. I don't think it is more difficult to remove the blue film than the paper film backing as suggested by another comment. You definitely need to leave one protective layer on until the gasket is positioned. The exposed adhesive grabs everything and it takes patients to get it positioned.

I am moderately experienced at opening Apple devices having replaced batteries in several iPhones, iPods, and an iPad. I could not get the watch open with the x-acto knife blade as shown. I found other sites showed using a 0.1mm thick tool. I bought one and found it relatively easy to open the watch. It has the advantage of going in horizontal rather than vertical so it went between the glass and the force sense gasket. Force sense gasket wasn't disturbed at all. iFixit should add this type of tool to their offering.