I'm having hard time to do the following substitution. Please help

diff(x(t), t, t) := -R*diff(psi(t), t)*diff(phi(t), t)*sin(phi(t)) + R*diff(psi(t), t, t)*cos(phi(t)) <---- this is my expression xdoubledot

I want to substitute it in following equation

`Eq__&lambda;1` := diff(x(t), t, t) - R*diff(psi(t), t, t)*cos(phi(t)) + R*diff(psi(t), t)*diff(phi(t), t)*sin(phi(t))  <----this is my equation

I have turned on physics and algebra mobdules. it still not substitiutes. even though you see diff here I have dots in my maple output I don't know why it changes when I copy paste here.

I tried subs, solve,simplify commands. None of them works

Thank you for your help in advance