How to re-sample project from a different bitrate in Cubase 5?

During prompt when it asks to convert, say yes.

Do you want to keep the source files in the pool directory?

When it asks to replace, say yes. (and all old projects are gone, hit NO if you want old projects to work)

Do you want to keep audio events at their sample positions?

When it asks about position, say no *OR* hit ‘YES’ listen, then UNDO from the Edit menu if not correct.