how to start over with respect to ports

[Jason Trickett]

I just want reset my ports and delete any that were built so far. Do I 
have to do it individually, or (hopefully) all at once. I want to go 
back to just using packages until I am more comfortable using the ports 
system. If answering please provide a detailed, easy-to-follow answer. 
I'd rather not have to reinstall the whole thing. Thanks.