i think you could search the forums and find the answer to your memory question...if not here then google
and yes there is a way to clear all sounds from memory and start a new beat. your manual should tell you that
but i go into TRIM mode, highlight the name field, hit open window, erase all samples.
then i go into PROGRAM mode, highlight the name field, hit open window, erase all programs
all this is easy stuff that can probably be found in your manual