I am trying to understand the concept of flips before learning the Bass Cancellation theorem. Let $R$ be a Noetherian ring and $P$ be a projective $R$ module. Let $p,q \in P$ , $\phi \in Hom(P,R)$ and $a \in R$. The automorphisms $(p,a) \mapsto (p+aq,a)$ and $(p,a) \mapsto (p,a+\phi(p))$ are called $\textbf{Flips}$.
Now the author says that they have a lifting property: If $I$ is an ideal of $R$, then every flip of $P/IP \bigoplus R/I$ over the ring $R/I$ can be lifted to that of $P \bigoplus R$. I am not understanding how should I prove this. Any help or hint would be much appreciated.