how to unload programs?

hello, could you help me on this?

after i've loaded some programs, just to hear them to see if they are ok for the song i'm doing, i reach quite quickly the max memory, i've only 16mb, so i would like to unload the programs i don't use to load new ones.

now i simply save the project and shut down the mpc than i turn it on and re load the project without the programs i don't use and i load new programs..

but i hope there is another way.. like the purge..

i would like also if there is another way to unload just some samples, not all the not used as the purge command does..

because maybe i haven't already putted in one program all the samples i've loaded but i want to leave them loaded because i think they will be used in the song i'm doing...

so, which is the best way to doing that without shutting down the mpc?

thanks!