it's not that difficult. though i wouldn't necessarily take the pedo route as many might find it "based". you'll have to get a sense for what their values are and what their own objections are. women are the easiest as most mildly intelligent muslimas are aware of just how bad islam is for women, and you only have to force them to come to terms with the dissonance, showing how christianity is the true alternative. but you'll have to get a feeling for who your interlocutor is. if they're on some dawah high, bombastic humiliation is the proper path. if they're genuinely curious, you can present the myriad of contradictions and ridiculous things in the quran + hadith, and be ready for when they try to pull the schrodinger's quranist ("i'm not a quranist until you show me embarrassing sahih hadiths").
Spain