为你解答如下：

▲第1种解决方案：

上面句子需要改为以下句子：

【1】I agree to abide by the terms and conditions stated on the following page

=I agree to abide by the terms and conditions (which were) stated on the following page

中文翻译：我同意遵守在第2页中声明/规定的条款。

【2】I agree to abide by the terms and conditions as (they are)stated on the following page

中文翻译：我同意按照第2页上所声明的/规定的条款来遵守.

(1)为一个定语从句省略了关系代词which+助动词were 结构

(2)为as引导的方式状语从句

(3) which/they都是指代the terms and conditions

▲第2种解决方案：

如果不想把as 去掉，就可以as stated 当作一个整体形容词作后置定语修饰前面的名词短语

as stated  adj.按照规定的

the terms and conditions on the following page按照第2页所规定的条款