Heros getting past lvl 10

I know heros can go past 10 in TFT just I can't figure out how, and also does any one know how to disable so that heros can gain levels from creeps after lvl 5, mostly wondering about how to get them past lvl 10, so any help thank you.

under game constants for both of em look for hero level sumtin or other and xp....jus look thru there...