Part of the point of open hardware is, you know, the open part. If you can’t open it, then it’s not open. iFixit tears apart popular consumer products, then rates them 1-10 based on how easy they are to work with. Apple seems to get pretty low scores (go figure) while Google seems to get pretty high scores (clips are better than glue). They also have a huge user community uploading instructions for repairing all sorts of things.