A) First PM waale icon pe click karo jo profile image ke bagal mein hai, tab neeche Show all ka option dikhega uspe click karo..
B) Then sabhi PM waale msgs show honge or sabhi msg ke saamne □ icon dikhega, uspe click karke msgs ko select karo (jo bhi delete karna hai)uch
C) Ab neeche choose action pe click Karke leave conversation ka option select karo.. Then GO pe click kar dena ho jaayega..