Simplify the following text for a Grade 11 native English-speaking person.
Original: Stefan Elmgren assumed the lead guitar and Patrik RÃ fling assumed the drums ( they joined the band in the end of 1997 after the release of Glory to the Brave album ) and Larsson decided to remain in the band until a suitable replacement for him was found .
Simplified: To fill the empty musical spots , Stefan Elmgren assumed the lead guitar and Patrik RÃ fling assumed the drums and Fredrik decided to remain in the band until a suitable replacement for him was found .