first, you need to have cleaning tools, maybe photoshop or anything similar. having drawing table is optional. and computer obviously.
then you just need to google it. there are many ways to clean raw manga and usually different people prefer different technique. so, just do your research a lil bit more. there are many cleaners that had uploaded steps and tutorials on how to clean raw manga. you can also watch videos on youtube. it is more easier that way. and nowadays, we have many filters that can make cleaning raw mangas easier. the redrawing part is the most challenging to me.
but, i think the most important is your commitment. if you wanna start cleaning raw manga and start joining any scanlation group, you gotta make sure you have enough time to do the work. and being open-minded when your works are being criticize. huhuhu~ *sorry-i-nag-too-much* i just wanna help* (●'◡'●)ノ
This is random but how do you clean raw mangas? I only know English but I was wondering if it's something you can do without knowing the language.