百煉千錘一根針， Tempered many times a needle is made

一顛一倒布上行。to go up and down through cloth.

眼晴長在屁股上， Its eye is located on the buttock,

只認衣冠不認人。 Identifying nobody but their raiments and hats. 

 PS. The poem is a sarcasm written against those snobbish guys.