Help! how can I change the tempo andkeep the time reference?

I was given a project that was originally done in Logic.
They exported OMFs, and opened them in Cubase, but the guy who did this before the project reached me didn’t set the Cubase tempo.
So now the tempo is the default 120bpm and if I change it to the real tempo (78), all the parts are moving and the song is basically f****d up!

There must be a way to do this right?
Please chime in if you know the solution!

Thanks

Oh I forgot to mention that I’m on C4.

Look up musical and linear time base

Make sure, no audio is in musical mode and all tracks are in linear timebase

Yep got it, thanks!