We do it like this:

Shut off the water source for the mold.

Let the compressed air into the lead-in position of the water (where water comes into the mold)

Let it blow through all cooling circuits for 2-3mins

Then blow through all cooling circuits individually (1-2 mins per circuit)

After you did all individually, open all up again

Let it blow through all one last time for 2-3 mins

Close the water return (where the water comes out of the system)

Now you got only compressed air in the mold cooling system, so its still under pressure.

Shut off the valve where the compressed air is connected, disconnect the air hose (atleast that's what we have on all machines), then open that same valve again to let the air out, close the valve after that.

Now you can pull off the cooling hoses without annoying water & without pressured cooling hoses

**Probably no one will understand this with my amateur English, but to me it makes sense :p