restore rom stock original 4.3 topic

My phone is current rom stock 4.4.2 ( new rom stock for i9500) and my phone is rooted. Now I want to restore rom stock original 4.3 . Can anyboby help me how to restore to 4.3. I read some thread they said they lost IMEI went they restore 4.3. So i afraid if i restore follow the step:
Bring my phone to Downloading mode --> up rom 4.3 by ODIN, i also lost IMEI.can i restore by this way? Thanks.