[Q] how to root galaxy s II plus ( GT-I9105 not P

[rajlove20]

i have a galaxy S II 19105 NOT P and i am new in this foram
firmware KSA
i bougt phone from KSA (KINGDOM OF Saudi Arabia).AND I tried for rooted
i used CWMtouch-i9105_chotu.tar.md5.zip with odin and successfull.
but when i flash superuser zip it say error
E failed to verify whole file signature
E (another error cant remeber)
then help me plez and tell me how to uninstall CWMtouch-i9105_chotu.tar.md5.zip and if not posible then how to flash superuser zip and make my phone rooted.sorry for my bad english
thanks...