My rule is I treat others how I want to be treated and generally I am a very nice person and get along with most people. Now that being said if someone disrespects me or my things then I no longer feel that I need to treat that person that way because they are not be nice to me. The first time I ask someone to do something or stop something I am usually patient and nice the next time I am not. After 7 months of his stuff being in the shed I would write him a letter stating that he has one week from today to get his junk out of the shed or else it will be considered abandoned and will be up to your digression to do whatever you want to with it. As for the other guy putting his junk on your stuff I would talk to him and tell him I asked you to move it you didn't and I had to, so in the future I would appreciate you not putting your stuff on mine.