It's difficult for old people to change their way of living.

Literal

Old-people [subject-が] lifestyle [possessive-の] way [object-を] change [nominalizer-の] [topic-は] difficult [copula-である].

~のは困難である nominalizes the act and declares it difficult. 生活の仕方 uses ~方 ('way of doing'). ~である is the formal copula.