's easier to change the sheets 
(ROOT (VP (VBZ 's) (ADJP (JJR easier)) (S (VP (TO to) (VP (VB change) (NP (DT the) (NNS sheets)))))))
(ROOT (VP (VBZ ) (ADJP (JJR )) (S (VP (TO ) (VP (VB ) (NP (DT ) (NNS )))))))