Question [Q] Xperia Z 4.2.2 pre-installed themes on 4.3

Hello XDA developers,

With regards to interesting facts read on your site, I decided to post my question here. I am totally new to XDA and I hope you guys will help for the concern I am here for.

A month ago I purchased Sony Xperia Z which was delivered with 4.1.2 jelly bean OS. I am totally new to Android OS. The pre-installed themes on this OS were amazing. The next update available was 4.2.2 which came with more themes and the list ended up with following themes:
Amber
Ruby
Sapphire
Emerald
Amethyst
Quartz
Silk
Xperia

With eagerness the device was updated to 4.3 and I am totally disappointed with the pre-installed theme pack.

Hence I started looking for solutions to get back the previous 4.2.2 themes on 4.3.

Please help me with this? Is it possible to get back those themes without voiding the warranty of the device?

Please provide the step by step procedure to accomplish.

Thanks and Best Regards,
Yogesh