The Apple Watch Series 6 earns a 6 out of 10 on our repairability scale (10 is the easiest to repair):

Screen replacements are difficult but possible. The screen is the first thing to come off, and detaches via ZIF connectors.

Battery replacements are reasonably straightforward, once you're inside.

Tiny tri-point screws throughout the watch can be difficult to remove and keep track of.

Several component flex cables are mounted directly to the S6 package, requiring skilled microsoldering to replace if they are torn.