How to reform from being a toxic player step by step guide by a reformed toxic player
DISCLAMIER: I do not condone acts of toxicity anymore so dont go commenting about me being toxic i'm reformed i have no intent of being negative to my team or putting them down this is all speculation after reading this does not give you immunity from getting banned in any way shape or form that all comes down to you as a player 
Step 1: Try not to solo que, Solo que is the bane of a toxic players existence because you never know how someones gonna do on your team and how you're gonna react to it. Solution to this is Dynamic que with some friends who are chill/not toxic AND MAKE SURE that you are in some sort of voice chat this will help with venting out rage of any kind. 
Step 2: This ones pretty obvious but DONT USE THE CHAT UNLESS ITS ABOUT OBJECTIVES OR YOU NEED HELP IN LANE trust me is flaming your support whos just missing everything and just having a bad game really worth your account getting banned forever/2 weeks thats a long time if you're a regular player. 
Step 3: Try not to que after having a stressful match, Take a break nap,snack,etc do something too get your mind off the game and ease your'self than que up when you feel relaxed and have it in your mind you're not gonna do anything toxic. 
Step 4: HAVE A POSITIVE ATTITUDE. Lets be real here most of us are not 100% positive all the time but i stress this TRY TRY TRY too just be nice and not do anything too drastic. Example every time some one gets a kill make sure to tell them Great job keep it up! or Nice job great work! etc this will reassure your team and give them confidence too keep improving as a player and drive others not to be toxic themselves 
Step 5: Play champions you have fun with not the champions that you expect too go positive with every time for example i main Zac so every now and then i take a break from him so i dont get over confident and think im undefeated champion if you have that mentality and you're getting upset from loosing as them try and break it asap this will only lead too you flaming/being negative. "Not too offend anybody that only plays one champion and is chill and takes it with a grain of salt just putting my thoughts on the matter :) " 
Last and final step is: DO NOT AND I REAPEAT DO NOT SAY GG EZ. This is possibly one of the most brushed over toxic words in the game and proably the most used this can lead too chat bans and 2 weeks so ALWAYS make sure its's gg or gg wp not "gg ez lmao you guys are so bad rekt" this will only lead too your demise 
And thats about everything sorry if i made some spelling errors French is my first language
just make sure too be positive and never flame and you should be good if you follow all these steps have fun!