n.k.s

I'm new with mods so if this is a noob mistake, please don't judge. I'm trying to make a space station and I'm trying to get my Kerbal to take large parts out of a storage unit. First, I don't know how and dragging it into my inventory is not an option as it is around 4 tonnes. Second, can I attach heavy parts or do I have to have more Kerbals to attach them.