Need HELP with TOPping, and another problem :)

HI all! well first of all i want to know if i can top my girl at this stage, and if i can. where to cut??!?! cause i never did that again
and my second problem, is that 2 bottom leaves are some of yellowing anyway i took a pic! thanks for your watching guys, any help would be appreciated

PS: the plant is Spicy White Devil a lil new strain and i couldnt find so much information :S
ALL PICS ITS THE SAME PLANT!

where to cut??





problem

5-6 node 1 more dude your primo!! theres a detailed thread here somewhere.. i'll link ya top it once then again and you end up with 4 colas!

not sure on diagnosis theres a thread here too!!

https://www.rollitup.org/marijuana-plant-problems/38772-guide-diagnosing-plant-problems.html should be of some help!