Reinitialize boss DR-550 MKII quick

i lent my friend my drum machine and he f*cked it up and now i cant get it to work. my friend that worked at a music store had one and he said that i need to reinitialize it but i cant figure out how and he doesnt remember, please help


b

See the DR-550 MKII Turbo Start which says to initialize the DR-550 MKII by .....

"Hold the -1/ and >/+1 buttons while powering up. This will restore the factory demonstration song, the factory patterns, sound edits and note number assignments."