Well I figure you'll need to install an ftpd, and grant yourself access.
The easier way would be (If you have already compromised the linux box), to just put the files you need on some anonymous webspace somewhere and download them from the box (I suppose you have shell access by now, right?) using wget.
If you decide to go with an ftpd, i recommend vsftp, I'm sure there are some smaller and easier ftpd's out there, but I don't know of any.
EDIT:
I just googled for it, and found
this list of linux (And BSD and some more) FTPd's. Go have a look, you might find something you like. Heck, there's even one written in
python
