Start up the disk drive emulator in the command line.
When "ready" lamp is lit, reset the machine's memory by pressing CE key, then type in 888, then press STEP key. This deletes all stored patterns, so be sure to back up first if you have patterns on the machine you want to save! (The patterns included with the machine are stored on non-rewritable chips and can never be deleted through this method).
Clear display with CE key, then prepare to load new data into memory by typing 551, then STEP.