I've seen multiple answers about kicking all of the other users but is there a way to stop the process id and kick just one user out of the database. Eg. user A B and C are connected to the database trying to generate reports but I only want C to stop and disconnect while A and B are still able to continue with their processes.
As a one-off you can use
EXEC sp_who or
EXEC sp_who2 or similar to find the SPIDs of that user's connections and then use
KILL <SPID> to stop them. Be aware that any transactions they have open in which changes have been made will need to be rolled back which could potentially take some time and be I/O intensive, but if they are just running reports the effect of this should be minimal. To stop them immediately restarting the processes disable their access before doing this (using
ALTER LOGIN <name> DISABLE or by adjusting their access rights more granularly).
If you find yourself needing to do this regularly you could write a procedure to automate the task, so you could just run
EXEC kick_user_off '<name>';, though if you need to do this sort of thing regularly enough for it to be worth the effort automating then I suspect you have a process and/or user problem that needs fixing of which this is just a symptom.