2000 Beetle TDI, Changing Battery

My battery terminals are corroded and I was going to take them loose to
clean them. Couldn't figure the terminal out. How do I get them off? I
took the nut off with the battery cable going to the terminal block on
top of battery box and the nut off of other side. I couldn't see anything
else to loosen them off of the battery posts. I know it is probably simple,
but its too cold outside to piddle with it!
Any tips, tricks,pictures or links to info would be appreciated!
Thanks

I am having that exact same problem on my 98 Beetle. Cold weather and everything. While cleaning the cake of corrosion on the positive terminal, I noticed further damage. The cable going from the positive terminal to the electrical box which sits on top was so corroded that it broke off. I cannot find the replacement part online and am considering splicing and applying electrical tape to bond the wire.... unless someone else has better advice for me.

Purchase the wire from the vw dealer. ITs problably a 5-10$ part. That wire is very needed because it supplies power to the main fuse box (on top of battery) which supplies power to all your main electrical consumers-
-coolant fans
-interrior fuse box
-headlights/tailights
-ecm

I bought a wire from Wal-Mart which I thought would fit. Unfortunately, I could not get the electrical box open without breaking it. So I just spliced the wire coming from the box with the new wire I bought and attached it to the battery. It works like a charm now. I had to charge the battery first, but at least my wire is not going to break again.