Question [Q] Steps to get back warranty

Hi, could someone write steps to possible return warranty ?
If I unlock bootloader I loose it, and I read when I flash stock ICS rom is impossible check bootloader status, but what with fastboot and recovery ?
How can I make it invissible in service ? Or if I flash stock ICS rom it will remove recovery ? Because I found recovery.img after extract KDZ...
Thanks for replies
Samsung Galaxy S3 16GB (I9300)

Rom: Blekota S5 Lite Beta 7
Android: 4.4.2
Root: Yes
Modem: GNA8
Kernel: AGNi pureSTOCK v4.6
CWM Recovery: PhilZ Touch 6 Recovery v6.48.4
Memory: ADATA 32 GB class 4

My work: MineBean V20P for LG Optimus L9