Edit the static\avatar.dat file
eg. using dos DEBUG

DEBUG AVATAR.DAT
E 12A 01 01
W
Q

Now, load the game as normal, and when you are in the game 
itself, access the cheats menus (yes, more than one....)

1 - Click left mouse button on yourself (the Avatar)
(gives you all the spells and such)

2 - Ctrl + F1, shows you all the combinations of keys to 
press in order to get all shields and weapons etc...

3 - Press F7 to access a pull down menu (lets you activate 
hackmover and such) Note ; if you are running the latest 
patch of Ultima 8, then you will have to use F9 (you can 
tell if you have this patch, try pressing F7, and if it 
saves the game, you have the patch)