Take out window that has a wiper blade mark in it.
 
FITS:
CHALLENGER MT455E, MT465E, MT475E, MT485E, MT495E, MT515D, MT525D, MT535D, MT545D, MT555D, MT565D, MT575D, MT585D, MT595D, MT515E, MT525E, MT535E, MT545E, MT555E, MT565E, MT575E, MT585E, MT595E
 
MASSEY FERGUSON 5609, 5610, 5611, 5612, 5613, 5709SL, 5709S, 5710SL, 5710S, 5711SL, 5711S, 5712S;, 5712S, 5713SL, 5713S, 5S.115, 5S.135, 5S.145, 6713S, 6714S, 6715S, 6716S, 6718S, 6S.145, 6S.155, 6S.165, 6S.180, 7614, 7615, 7616, 7618, 7619, 7620, 7622, 7624, 7714, 7714S, 7715, 7715S, 7716, 7716S, 7718, 7718S, 7719, 7720, 7720S, 7722, 7722S, 7724, 7724S, 7726, 7726S, 7S.155, 7S.165, 7S.180, 7S.190, 7S.210