Well, I have figured it out:
A=B
B=C
C=D
D=E
E=F
F=G
G=H
H=I
I=J
J=K
K=L
L=M
M=N
N=O
O=P
P=Q
Q=R
R=S
S=T
T=U
U=V
V=W
W=X
X=Y
Y=Z
Z=A.
Now easy? Now use that to translate those files!

Skype wrote:[7:23:42 AM] Darx: Click here to give me an internet!
[7:23:57 AM] 'a'a: *clicks here*