Simplify the following text for a Grade 6 native English-speaking person.
Original: The current line-up features long-time lead guitarist Kirk Hammett ( who joined the band in 1983 ) and bassist Robert Trujillo ( a member since 2003 ) alongside Hetfield and Ulrich .
Simplified: Burton later joined the band after Ulrich and Hetfield saw him in a concert . In 1983 , Mustaine was kicked out of the band and replaced with guitar player Kirk Hammett .