same as on the PW 1 I would imagine.
rebuild a cramfs with the stuff you want in it and shove it on,
CAVEATS:
A) I have never done it
B) cramfs is readonly, so you will have to make one
C) there are threads on this for the PW1
D) I have NO idea how to activate the new fonts if you added them (note A & C above)
Hope it helps.
SEE:
https://www.mobileread.com/forums/sho...44&postcount=6