Lessen hardness of college entrance — one gets in (8)
I believe the answer is:
mitigate
'lessen hardness' is the definition.
'college entrance one gets in' is the wordplay.
'college' becomes 'mit' (I've seen this in other clues**).
'entrance' becomes 'gate' (I've seen this before).
'one' becomes 'i' (Roman numeral).
'gets in' indicates putting letters inside.
'mit'+'gate'='mitgate'
'mitgate' enclosing 'i' is 'MITIGATE'.
'of' acts as a link.
(Other definitions for mitigate that I've seen before include "Appease" , "Mollify" , "Lessen - modify" , "Reduce the severity of, say a sentence" , "Lessen the seriousness of" .)