If you installed in the default place, the path is like:
C:\Program Files\
The Game Creators\FPS Creator\Files\entitybank\scifi\
characters
(The important parts are in bold)
Find the
.FPE file of the character you want to scale and open it in a text editor.
where it says:
;orientation
model = aiko.x
offx = 0
offy = 0
offz = 0
rotx = 0
roty = 0
rotz = 0
scale = 90
fixnewy = 180
Change the value of
scale to 90 (for 90%) or whatever you want. I haven't tried it but you can probabily set that value higher than 100 if you want really big enemies but the translation (movement) might look wierd.
Good luck!