从语法角度讲,you thinking是 style 的定语,但是you thinking是带有逻辑主语的分词的独立主格结构,而独立主格结构只能作状语,不能用作定语,应该改为定语从句或者“of + 动名词”.
You need to change the style (that) you think. (= in which you think)
You need to change the style of thinking.
从修辞角度讲,style 指“流行的或为人喜爱的风雅方式”,即“风格”、“时尚”或“优雅方式”.如果表示“思维方式”或“思想方法”,最好改为mode(由传统或习俗影响而遵循的方法)或way,即——
You need to change the mode of thinking.
You need to change the way of thinking.