LTM Software Upgrade from 10.2.4 to 11.6

Team,

 

LTM 3900 is running with software version 10.2.4, since this is very old image, we are in plan to upgrade the same with latest version. atleast 11.6.

 

seeking guideline me step by step. So that after upgradation it should work as it is working now.

 

Thanks.