Note edge 915G , downgrade from 6.0.1 to 5.1

Hi ,
i am new to this forum, i have note edge 915G ,not rooted.

Can you please guide me how to downgrade from firmware 6.0.1 to lolipop,
i am going to lolipop because with 6.0.1 battery drain very fast even with 100% charge it stay for 4-5 hr.

Need your help.