new hd zuner here ?

[mpy041]

so i've got a collection of 1700 songs in my laptop that i uploaded from my old zune 30g i've lost it and now upgrading to a 16g HD zune, (used) the guy tells me he has a ton of random music and tells me i can have whats in it so now my question is I already have the software and my 1700 tracks just waiting on my zune Hd to arrive so am wondering if when i do get it how can i upload the stuff he had on the zune and just add it to my already decent collection, without erasing my old stuff ( icant get it back if i somehow mess up and delete it)