Installing a new rom to my tablet

[ofcourse]

I want to install a new rom to my android tablet.There are necessary instructions and files.One of the files are rockchip batch tool v1.5 and other is a disc image file named rom.

It says

1- load the drivers
2-select the img file (rom) in batch tool
3-install it to device by clicking restore.

Is this enough or should i delete the rom that is already loaded in my tablet.Like when we format the old OS in computers?

My tablet uses android 4.1.1

Thanks in advance.

 

[Rukbat]

1) There's no need to format the drive in a computer when you're installing a new OS. You might have to repartition the drive, and repartitioning, not installing a new OS, requires formatting.

2) Clear all caches (system and dalvik) in recovery before installing the new ROM. Install the ROM according to instructions. Clear all caches. (Yes, both before and after installing.) Reboot to the new ROM. Let the phone sit for at least 10 minutes after the ROM has finished booting the first time, before trying to do anything.