Default how to revert back from cm11 to cm10.2

hey,
I updated my phone to cm11 using proper method.
cm11 got installed and I was able to use it
But there are lots and lots of issues in cm11 that I am currently facing for example camera not working,apps don't get installed etc
I m not satisfied with cm11 but cm 10.2 was totally awesome..thanks to xda for helping me in installing cm10.2...
I tried to figure out the issues but ended up being unsuccessful
I want to reinstall cm10.2
phone Samsung s2 gt-i9100g
please help me to solve this issue
PLEASE PLEASE PLEASE