I've answered my own question, but I'll put it on here in case anybody else needs to do it.
A torx size of T60 is needed, along with a 3 rubber o ring kit ordered from a jeep supplier, apparently quite a normal place for the older zg to leak.
Thanks to this website
http://www.lunghd.com/Tech_Articles/...nt_O-Rings.htm.
Also, lots of info from the american jeep websites.