adapt:1)to make sth suitable for a new need or purpose
2)to change your behaviour or ideas to fit a new situation
eg:He adapted an old car engine to use in his boat.
adjust:1)to correct or slightly change the position of sth
2)to change to suit a particular situation or new condition
eg:He adjusted his tie.
accustom:to make someone used to sth
eg:He had to accustom himself to the cold weather ofhis new city .